Non-toxic corrosion-protection conversion coats based on rare earth elements

ABSTRACT

Conversion coatings comprising a rare earth element and a valence stabilizer combined to form a rare earth/valence stabilizer complex are described for substrate metals. The rare earth element is selected from cerium, praseodymium, terbium, or combinations thereof, and at least one rare earth element is in the tetravalent oxidation state. The coating bath may also contain a preparative or solubility control agent. The oxidized cerium, praseodymium or terbium is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. A number of cerium, praseodymium, or terbium/valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of commonly assigned U.S.application Ser. No. 10/038,274, filed Jan. 4, 2002, now U.S. Pat. No.7,294,211 and entitled “NON-TOXIC CORROSION-PROTECTION CONVERSION COATSBASED ON COBALT.” This application is also related to U.S. applicationSer. No. 10/625,885, filed Jul. 23, 2003, now U.S. Pat. No. 7,291,217 B2and entitled “NON-TOXIC CORROSION-PROTECTION PIGMENTS BASED ON RAREEARTH ELEMENTS”, which is a continuation-in-part of U.S. applicationSer. No. 10/037,576, filed Jan. 4, 2002, now abandoned, and entitled“NON-TOXIC CORROSION-PROTECTION PIGMENTS BASED ON COBALT”, and U.S.application Ser. No. 10/625,886, filed Jul. 23, 2003 and entitled“NON-TOXIC CORROSION-PROTECTION RINSES AND SEALS BASED ON RARE EARTHELEMENTS”, which is a continuation-in-part of U.S. application Ser. No.10/038,150, filed Jan. 4, 2002, now U.S. Pat. No. 7,235,142, andentitled “NON-TOXIC CORROSION-PROTECTION RINSES AND SEALS BASED ONCOBALT”, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates generally to compositions and methods for theformation of protective, corrosion-inhibiting coatings on metals, orother materials coated with metals, without the use of chromium in thehexavalent oxidation state. More particularly, this invention relates tonon-toxic, corrosion-inhibiting conversion coatings based on tetravalentcerium, praseodymium, or terbium and methods of making and using thesame.

Metals like aluminum, zinc, magnesium, titanium, cadmium, silver,copper, tin, lead, iron, rare earths, zirconium, beryllium, niobium,tantalum, lithium, or indium, their alloys, or items coated with thesemetals, tend to corrode rapidly in the presence of water due to theirlow oxidation-reduction (redox) potentials or ease of oxide formation.Non-alloyed specimens of these metals typically form a natural oxidefilm that will protect them somewhat and reduce their overall rate ofcorrosion. However, alloys of these metals are particularly sensitive tocorrosive attack. These materials also have a significant problem withpaint adhesion. The as-formed metal surfaces are typically very smooth,and they tend to form weakly bound surface oxides. The native oxides donot normally provide a robust base on which subsequent paints can anchorthemselves. These metal alloys have many uses ranging from architecturaladornments, to protective coatings on ferrous alloys, to structuralaerospace components, inter alia.

The 2000 and 7000 series of aluminum alloys are used throughout militaryand civilian aircraft because of their high strength to weight ratio.However, these aluminum alloys are very sensitive to corrosive attackbecause their natural oxide layer offers only a limited degree ofprotection. Materials with greater redox potentials, such as steels orcarbon fibers, in proximity to aluminum alloys will promote corrosiveattack in water by the formation of a galvanic corrosion couple with theless-noble light metal alloy.

Inhibiting the initiation, growth, and extent of corrosion is asignificant part of component and systems design for the successfullong-term use of metal objects. Uniform physical performance and safetymargins of a part, a component, or an entire system can be compromisedby corrosion.

One method of enhancing the corrosion resistance of these alloysincludes the use of a conversion coating. A conversion coating is aself-healing, corrosion-inhibiting layer formed during intentionalexposure to a chemically reactive solution. The conversion coatingprocess forms an adherent surface containing an integral corrosioninhibitor with “throwing power” that can provide protection to coatingbreaches. The metal is exposed to a compound that chemically alters thesurface and forms a coating that provides a high degree of corrosionresistance. A chemical conversion coating applied to the surface of aless-noble alloy can reduce the extent and severity of aqueouscorrosion, provide long-term property stability, and extend the usefullife of the object of manufacture.

Conversion coatings incorporate a portion of the base metal and form amechanical, chemical, and electrostatic barrier to corrosive attack. Afeature of effective conversion coatings is their ability to providecorrosion protection to the base metal in the presence of a coatingbreach.

Anodization of a metal surface followed by “sealing” or “rinsing” of theanodized metal does not constitute the formation of a conversion coatingin our usage. Anodization, the formation of a porous oxide film on themetal, is achieved by the application of an electrical potential to themetal. This oxide film must then be “sealed”, “washed”, or “rinsed” inorder to impart complete corrosion protection. Typically, the corrosionprotection afforded by an anodized piece is due to the barrier oxidefilm. Conversion coatings, however, grow an oxide coating on the metalwithout an externally applied electrical potential. The protective filmis produced by a chemical redox reaction between the metal surface andthe conversion coating solution. The film is composed both of an oxideand integral corrosion inhibitor species formed during exposure to theconversion coating solution. A true conversion coating therefore affordscorrosion protection from an oxide barrier film that has co-depositedoxidative corrosion inhibitor species.

A conversion-coated surface may be left bare or afforded furtherprotection by the application of additional films or coatings.Conversion coatings need to adhere to the substrate and should result ina surface that will promote the formation of a strong bond withsubsequently applied coatings. Bonding with subsequently appliedcoatings is a function of the morphology and chemical composition of theconversion coating. Adhesion promoting surface treatments may exhibitcorrosion-inhibiting characteristics. Depending on the intendedapplication, a conversion coating, as described herein, may beconsidered to be an “adhesion promoter” and vice versa.

Conversion coatings are usually formed by the application of aconversion coating solution to a metal surface. The solution can beapplied by immersion, spray, fogging, wiping, or other means.

Hexavalent chromium has traditionally been used in the formation ofprotective conversion coatings for aluminum, zinc, magnesium, titanium,cadmium, silver, copper, tin, lead, iron, rare earths, zirconium,beryllium, indium, and their alloys. Compounds such as Alodine®(available from Henkel Surface Technologies, Madison Heights, Mich.) andAlumigold™ (available from Turco Products, Inc., Madison Heights, Mich.)contain hexavalent chromium as their main corrosion-inhibiting compound.

Two generic types of hexavalent chromium coatings have been widely used.The newer “gold” coatings are named for the faint gold tint that isexhibited when these coatings form on the surface of aluminum alloys.The compositions and application procedures of these “gold” hexavalentchromium conversion coating formulations are described in United Statesmilitary process specifications, as well as other federal guidelines.Therefore, guidelines for the application of these solutions to aluminum(MIL C-5541; MIL C-81706; MIL STD-171; ASTM B-449), zinc (ASTM B-633;ASTM B-201; MIL C-17711; QQ Z-325a), magnesium (MIL M-3171), cadmium(ASTM A-165; ASTM B-201; QQ P-416b), silver (ASTM B-700; QQ S-365a),copper (ASTM B-281), and tin (ASTM A-599; QQ-T-425a) are available. Thecommon components to these “gold” conversion coating baths arehexavalent chromium, complex fluorides, and ferricyanide. Older “green”conversion coatings containing hexavalent chromium have also beendescribed, and the color formed on aluminum alloys through theapplication of these conversion coatings is a light green color. The“green” formulations all contain hexavalent chromium, a fluoride, and anacidic phosphate component. The major compositional difference betweenthe two is that the current “gold” formulation contains ferricyanide andthe older “green” formulations contain phosphate.

Corrosion-resistant compositions have also been described which containhexavalent chromium, fluoride, and molybdic acid or molybdates, ratherthan ferricyanide or phosphate. Tungstates and vanadates have also beenused in combination with hexavalent chromium and fluoride. Hexavalentchromium formulations which do not contain a fluoride source, and whichcontain borate ions instead of ferricyanide or phosphate or molybdatehave also been described. Hexavalent chromium has also been used incombination with stannates, oxalates, and tellurates. Finally, corrosionprotection of aluminum, magnesium, or zinc alloys has been achievedthrough the use of hexavalent chromium, fluoride, and rare earthcompounds.

The variation in the type and amount of additional components such asferricyanide, phosphate, molybdate, and borate, etc., in conversion coatformulations based on hexavalent chromium is significant in light of thechemistry developed and presented in the present invention. It isimportant to note that hexavalent chromium conversion coatings whichhave nearly identical formulations, except for one or more of thenon-chromium components, result in obvious differences on the appliedmetal surface for a given alloy (such as “gold” and “green” coatings).It is also important to note that differences in the composition ofaluminum alloys will influence the chemistry of the conversion coatingformed when only one hexavalent chromium conversion coat composition isused.

Significant efforts have been made to replace chromium with other metalsfor corrosion-inhibiting applications due to toxicity, environmental,and regulatory concerns. Cerium is one non-toxic, non-regulated metalwhich has been considered as a chromium replacement. Cerium (likechromium) exhibits more than one oxidation state (Ce⁺³ and Ce⁺⁴). Inaddition, the oxidation-reduction potential of the Ce⁺⁴—Ce⁺³ couple iscomparable to the Cr⁺⁶—Cr⁺³ couple. For example, in acid solution:Ce⁺⁴+e⁻→Ce⁺³+1.72 VCr⁺⁶+3e⁻→Cr⁺³+1.36 V

Praseodymium and terbium also exhibit more than one oxidation state(Pr⁺³ and Pr⁺⁴, Tb⁺³ and Tb⁺⁴). Tetravalent praseodymium and terbium areeven stronger oxidizing agents than cerium (with calculated redoxpotentials of +3.3 V in acidic solution (Nugent, L. J., et al., J Inorg.Nucl. Chem. 33: 2503-30, 1971):Pr⁺⁴+e⁻→Pr⁺³+3.2 VTb⁺⁴+e⁻→Tb⁺³+3.2 VCr⁺⁶+3e⁻→Cr⁺³+1.36 VA number of processes have been reported in the literature that make useof cerium in conversation coating bath solutions, as well as generalcorrosion protection or coloring of the alloys. However, the coatingsformed by these processes provide only limited protection and do notapproach the benefit derived from the use of hexavalent chromium.

The use of film-forming substances, such as polymers, silicates,sol-gel, etc., which have no inherent oxidizing character, in conversioncoating solutions has been described in the literature. The film formersmay enhance short-term corrosion resistance by functioning as a barrierlayer. However, these films interfere with substrate oxidation duringthe conversion coating process and produce thin, incompletely anodizedsurfaces, resulting in poor mechanical adhesion to thesolution-deposited polymer film and to later applied coatings.Restricting the formation of the oxide layer that acts as a reservoirfor the active corrosion inhibitor yields a barrier film that isinhibitor starved. Barrier layers lacking an active corrosion inhibitorhave been demonstrated to be capable of inhibiting corrosion only aslong as the barrier is not breached, as by a scratch or other flaw. Filmformers can actually enhance corrosion on a surface after failure due tothe well-known effects of crevice corrosion. The addition of polymerduring conversion coating also produces a smooth coating which canreduce subsequent paint adhesion, resulting in reduced long-termcorrosion protection.

Likewise, a myriad of inorganic oxide, phosphate, silicate, carbonate,ox al ate, molybdate, tungstate, zirconate, titanate, borate, etc.barrier films have been described in the literature as providingcorrosion protection. However, these films will serve this function solong as the film or coating is not breached to expose bare metal. Shouldthis occur, none of these coatings exhibit “self-healing”characteristics. For example, hexavalent molybdenum (Mo⁺⁶) found inmolybdate or heteropolymolybdate coatings does not exhibitoxidation-reduction potentials comparable to hexavalent chromium (i.e.,in acidic media, Mo⁺⁶+3e⁻→Mo⁺³, potential is +0.43 V; or Mo⁺⁶+2e⁻→Mo⁺⁴,potential is +0.65 V). Similarly, hexavalent tungsten (W+⁶) found intungstate or heteropolytungstate coatings does not exhibitoxidation-reduction potentials comparable to hexavalent chromium (i.e.,in acidic media, W⁺⁶+2e⁻→W⁺⁴, potential is −0.12 V). In order to matchthe oxidation-reduction potential of hexavalent chromium, tetravalentcerium must be present in the coating.

U.S. Pat. Nos. 5,635,084, 5,582,654 and 5,194,138, all to Mansfield etal., describe methods for treating the surface of an aluminum alloyhaving a relatively high copper content, so as to make the surfaceresistant to corrosion. The method comprises a) removing substantiallyall of the copper from the surface of the alloy, b) contacting thesurface with a first solution containing cerium, c) electricallycharging the surface while contacting with an aqueous molybdatesolution, and d) contacting the surface with a second solutioncontaining cerium. However, tetravalent cerium is not disclosed.

European Application No. EP 0 792 922 A1, by The Boeing Company et al.,describes chromate-free, corrosion-inhibiting coatings for protection ofaluminum and its alloys comprising a) a film-forming organic polymericand/or sol-gel component, b) an ester of a rare earth metal, i.e.,cerium, or a vanadate salt of an alkali or alkaline earth metal, and c)a borate salt of an alkali earth metal. The film-forming organicpolymeric or sol-gel component may provide short-term corrosionresistance by functioning as a barrier layer. However, these filmsusually interfere with substrate oxidation during the conversion coatingprocess and result in thin, incompletely anodized surfaces, resulting inpoor mechanical adhesion to the solution-deposited polymer film and tolater applied coatings. Polymers added during the coating process alsoproduce smooth coatings with a limited amount of “rough” surfacemorphology for subsequent paint adhesion resulting in reduced long-termcorrosion protection. Neither the importance of tetravalent cerium northe functional parameters for tetravalent cerium-containing complexesare described.

Similarly, U.S. Pat. No. 5,192,374 to Kindler describes the formation ofan aluminum oxide (boehmite) coating on structural aluminum, followed bytreatment with a soluble cerium salt and a metal nitrate at 70° C. to100° C. to form cerium oxides and hydroxides for increased corrosionresistance. The formed oxides and hydroxides are described as fillingthe pores in the boehmite coating. Also, Stoffer et al. in U.S. Pat. No.5,932,083 describe the use of a solution containing cerium and anoxidizing agent for treatment of aluminum alloys. Thealuminum-containing substrate is electrolyzed in this solution, forminga mixed aluminum oxide/cerium oxide (or hydrated cerium oxide) coatingon the aluminum as a barrier film. The formation of tetravalent orhydrated tetravalent cerium oxide is described. However, neither Kindlernor Stoffer et al. teach the use of “valence stabilizers”, which areimportant for use of tetravalent cerium compounds having aqueoussolubilities that are sufficiently high to ensure long-term self healingof the coating. The cerium oxides and hydrated oxides described in thesepatents function merely as pore-filling barrier layers and not as activeself-healing inhibitors within the coating. Moreover, the use oftetravalent cerium oxides and hydroxides as corrosion inhibitors resultsin lower corrosion performance, as is described herein, due to the factthe electrostatic double layers around such oxide and hydroxide speciesare much smaller than those exhibited by tetravalent cerium speciescontaining 50% or less oxide or hydroxide as attached ligands.

Similarly, PCT International Publication No. WO 88/06639 by theCommonwealth of Australia and U.S. Pat. No. 6,022,425 to Nelson et al.describe the application of a corrosion-resistant coating for aluminumbased on cerium, which cerium is oxidized to the tetravalent oxidationstate, resulting in the formation of tetravalent or hydrated ceriumoxides. However, these references teach tetravalent cerium compoundshaving aqueous solubilities that are so low they function as barrierfilms or sealants, rather than active corrosion inhibitors. Moreover,the use of valence stabilizers for forming complexes with tetravalentcerium is not disclosed.

European Patent Application No. EP 0 902 103 A1 by Nippon SteelCorporation describes the application of a trivalent cerium solutionwith organic oxoacids to aluminum or galvanized steel. U.S. Pat. No.6,190,780 B1 to Shoji et al. describes the use of rare earth and/orGroup IVA solutions for the treatment of metal surfaces with oxyacids(i.e., molybdates, tungstates, vanadates, or phosphates). Likewise, U.S.Pat. No. 6,200,672 B1 to Tadokoro et al. describes the use of rare earthand/or Group IVA solutions with selected organic molecules for treatmentof metal surfaces. U.S. Pat. No. 5,964,928 to Tomlinson describes theuse of a Group IVA compound (i.e., zirconium, titanium, or hafnium) incombination with a rare earth element and optionally a fluoride. Also,U.S. Pat. No. 6,503,565 B1 to Hughes et al. describes the use of aqueousacidic, rare earth ion-containing coating solutions for metal surfaces.The coating solutions can include rare earth cations capable of havingmore than one valence state. However, none of these references teach thepresence of a valence stabilized, oxidized rare earth element such ascerium, praseodymuim, or terbium in the formed conversion coating, whoseavailability to the corroding system is controlled via the solubility ofthe oxidized rare earth compounds. In order to function as a truereplacement for hexavalent chromium, which is itself a highly oxidizedspecies, the rare earth compound must be oxidized in the formed coating.

U.S. Pat. No. 6,206,982 B1 to Hughes et al. describes the use of a fourcomponent system to provide corrosion protection of aluminum. One ofthese components includes a rare earth compound, especially cerium.

The use of colloidal suspensions of tetravalent cerium oxide (CeO₂) inanticorrosive coatings is described in U.S. Pat. Nos. 5,733,361 and5,922,330 to Chane-Ching et al.; PCT International Publication No. WO96/26255 by Rhone-Poulenc Chimie; and PCT International Publication Nos.WO 01/36331 A1 and WO 01/38225 A1 by Rhodia Terres Rares. The CeO₂exhibits a solubility that is too low for effective release ofcorrosion-inhibiting tetravalent cerium ions.

An aqueous dispersion of a cerium compound with other rare earths,transition metals, aluminum, gallium, or zirconium is described foranticorrosive agents in PCT International Publication No. WO 01/55029 A1by Rhodia Terres Rares. Similarly, an aqueous dispersion of cerium oxidein combination with additives such as beta-diketones,alpha-hydroxycarboxylic acids, beta-hydroxycarboxylic acids, or diols isdescribed for anticorrosive agents in U.S. Pat. No. 6,033,677 to Cabaneet al. Neither of these references defines the need for cerium to be inthe tetravalent oxidation state to achieve anticorrosive effects.

U.S. application Publication Ser. No. 2003/0,024,432 A1 by Chung et al.describes an anti-corrosive surface treatment comprising, inter alia, anorganometallic compound that can include cerium (i.e., cerium acetatehydrate, cerium acetylacetonate hydrate, cerium 2-ethylhexanolate,i-propoxycerium, cerium stearate, and cerium nitrate). The disclosedcoating is an anti-corrosive sol-gel that produces an adhesive filminterface between a metal surface and an organic matrix resin oradhesive. In addition, U.S. application Publication Ser. No.2003/0,019,391 A1 by Kendig describes a corrosion inhibitor comprisingan oxo-anion and a cation that is capable of inhibiting the propagationof pit corrosion on the surface of coated metal substrates. The cationcan be a rare earth metal including cerium and praseodymium, inter alia.However, neither Kendig nor Chung et al. describe the need for cerium tobe in the tetravalent oxidation state for corrosion inhibition.

Accordingly, a need exists for improved corrosion-protection conversioncoatings composed of currently unregulated and/or non-toxic materialswhich have an effectiveness, ease of application, and performancecomparable to coatings formed with hexavalent chromium, and for methodsof making and using the same.

SUMMARY OF THE INVENTION

This need is met by the present invention which represents a significantimprovement in the formulation of non-toxic conversion coatings throughthe use of tetravalent cerium, praseodymium, or terbium. Although thepresent invention is not limited to specific advantages orfunctionality, it is noted that the conversion coatings of the presentinvention inhibit corrosion to a higher degree than any other knowncerium-based coatings. Moreover, the coatings inhibit corrosion to adegree comparable to commercial formulations based on hexavalentchromium. They do not require the use of elevated temperatures, orexotic materials or application methods.

The present invention utilizes “valency stabilization” of thetetravalent cerium, praseodymium, or terbium ions in the as-formedconversion coatings to achieve corrosion resistance that is comparableto hexavalent chromium. More specifically, in order to achieve a highdegree of corrosion resistance, a conversion coating can exhibit thefollowing characteristics:

-   1) The coating can contain an oxidizing species. Oxidizing species    serve two important functions within the coating: a) they act to    impede the flow of charged species through the coating, therefore    helping reduce the transport of corrosion reactants, and b) if a    scratch is formed in the coating, these oxidizing species act to    “repair” the breach by oxidizing the underlying metal and quickly    reforming an oxide barrier. The effectiveness of oxidizing species    is a function of their individual oxidation-reduction potential, and    the more highly oxidized species exhibit greater corrosion    protection. An oxidation-reduction potential of approximately +0.80    V (at a pH of 0) appears to be the dividing line between inhibitors    that offer some corrosion protection and those that do not. The    tetravalent cerium ion, with an oxidation-reduction potential of    +1.72 V (at a pH of 0), is an exceptionally good oxidizing species.    The hydroxyl and oxygen liberated from water when tetravalent cerium    is reduced will oxidize (“passivate”) nearby bare metal. Tetravalent    praseodymium or terbium, with oxidation-reduction potentials of    approximately +3.2 V, are even stronger oxidizers that exhibit an    even higher tendency to passivate nearby metal.-   2) A “valence stabilizer” for the tetravalent cerium, praseodymium,    or terbium can be employed to ensure that the ion will not be    reduced quickly to the trivalent state in solution or in the    coating. The importance of stabilizing the cerium ion in its    tetravalent state in a solid precipitate was not previously    recognized as important to the formation of a conversion coating.-   3) The tetravalent cerium, praseodymium, or terbium species formed    in the coating should be present as a “sparingly soluble” material.    If the formed tetravalent cerium, praseodymium, or terbium species    is too soluble, then it will be washed away. If it is too insoluble,    then insufficient tetravalent cerium, praseodymium, or terbium is    available to inhibit corrosion. A tetravalent cerium, praseodymium,    or terbium species that exhibits low solubility will not only fail    to inhibit corrosion, but can promote localized crevice corrosion    and result in enhanced corrosion rates. In order to form an    effective conversion coating, the tetravalent cerium, praseodymium,    or terbium compounds formed in the coating must be in a “sparingly    soluble” form. It is difficult to place specific solubility values    to these optimum “sparingly soluble” coating materials because there    appear to be several variables associated with what makes an optimum    coating material. If the tetravalent cerium, praseodymium, or    terbium is incorporated in the coating in the form of a tetravalent    cerium, praseodymium, or terbium/valency stabilizer complex, which    exhibits a solubility in water of between about 5×10⁻⁵ and about    5×10⁻² moles per liter of tetravalent cerium, praseodymium, or    terbium, then appreciable corrosion inhibition will be observed.    Coatings that incorporate stabilized tetravalent cerium,    praseodymium, or terbium compounds that fall outside of this    particular solubility range may also exhibit some corrosion    inhibition. For example, compositions with solubilities as high as    5×10⁻¹ moles per liter or as low as 1×10⁻⁵ moles per liter of    tetravalent cerium, praseodymium, or terbium at standard temperature    and pressure, exhibited some corrosion resistance, although not as    great as those compounds which fall within the optimum solubility    range. The degree of effectiveness will depend on the particular    compound itself. The solubility characteristics of the tetravalent    cerium, praseodymium, or terbium in the conversion coatings must be    controlled through the use of stabilizer materials which form    compounds that fall within a desired solubility range. In this way,    a “controlled release” of tetravalent cerium, praseodymium, or    terbium can be achieved, much as a “timed release” of hexavalent    chromium is achieved in the state-of-the-art systems.-   4) The “valence stabilizer” helps establish an electrostatic barrier    layer around the cation-stabilizer complex in aqueous solutions. The    nature and character of the electrostatic double-layer surrounding    the cation-stabilizer complex may be controlled and modified by    careful selection of stabilizer species. Characteristics such as the    electrical dipole moment and the shape/conformation (for steric    effects) of the stabilizer were found to influence the performance    of the conversion coating. In general, the electrostatic double    layer formed acts to protect the cation from premature reaction with    hydronium, hydroxide, and other ions in solution. The formation of    electrostatic barrier layers also helps to impede the passage of    corrosive ions through the conversion coatings to the metallic    surface.

This phenomena is exhibited in the hexavalent chromium systems, whereinthe highly charged hexavalent chromium is surrounded by very polarferricyanide ions. The orientation of the dipoles of the ferricyanideions with respect to the highly charged chromate ion serves to attractadditional layers of ions in the aqueous solution. These ions form aprotective shell around the cation-stabilizer complex.

-   5) The coating material may also exhibit ion exchange behavior    towards alkali species. This optional consideration is important for    the formation of conversion coatings which resist corrosion because    alkali ions (especially sodium) are notoriously corrosive towards    alloys which contain metals such as aluminum, magnesium, or zinc.    The hexavalent chromium-ferricyanide complex formed in the    conventional systems also exhibits this ion exchange phenomena.

The corrosion resistance of a number of aluminum alloys as tested usingboth ASTM B-117 and ASTM G-85 has been enhanced through the use ofstabilized tetravalent cerium, praseodymium, or terbium conversioncoatings. Not only do these optimized coatings retard corrosion to ahigher degree than other known tetravalent cerium baths, but theircorrosion resistance is comparable to that of hexavalent chromiumsystems. Unlike the prior art, the tetravalent cerium conversioncoatings of the present invention do not result in the formation ofcerium oxide or hydrated cerium oxide barrier layers with no activecorrosion-inhibiting functionality.

The valence stabilizers can be inorganic or organic. A multitude oforganic and inorganic stabilizer materials have been used.

In one aspect, the invention comprises a mechanistic and chemicalapproach to the production of corrosion-resistant conversion coatingsusing tetravalent cerium, praseodymium, or terbium. This approach usesstabilizer materials which form compounds with tetravalent cerium,praseodymium, or terbium that are sparingly soluble in aqueous solution,typically from about 5×10⁻² to about 5×10⁻⁵ moles/liter of tetravalention. This solubility range provides a release of tetravalent cerium,praseodymium, or terbium at a rate sufficiently slow enough thatprotection will be provided for an extended period of time and fastenough to inhibit corrosion during conventional accelerated corrosiontesting methods such as ASTM B-117 and ASTM G-85 for conversioncoatings. Compounds that fall slightly outside of this solubility range(as high as 5×10⁻¹ to as low as 1×10⁻⁵ moles/liter of tetravalentcerium, praseodymium, or terbium at standard temperature and pressure)may also prove to be effective conversion coatings under certainconditions. However, compounds that exhibit aqueous solubilities faroutside of the target range are unlikely to be effective corrosioninhibitors. The solubility of the formed tetravalent cerium,praseodymium, or terbium compounds plays a significant role in theeffectiveness of the formed coating. Solubility control can be achievedusing organic or inorganic stabilizer materials.

In another aspect, the invention is the achievement ofcorrosion-resistant conversion coatings using tetravalent cerium,praseodymium, or terbium. This approach also utilizes stabilizermaterials, which form compounds that exhibit dipoles so as to formelectrostatic barrier layers composed of ions, such as hydronium (H₃O⁺)or hydroxide (OH⁻). The formation of these barrier layers through theuse of stabilizer materials can be achieved using organic or inorganicmaterials.

In an optional aspect, the invention is the achievement ofcorrosion-resistant conversion coatings using tetravalent cerium,praseodymium, or terbium by the use of stabilizer materials, which formcompounds that exhibit ion exchange behavior towards alkali ions. Theformation of this ion exchange behavior can be achieved through the useof organic or inorganic materials.

In another optional aspect, the invention is the achievement ofcorrosion-resistant conversion coatings using preparative agents inconjunction with the cerium, praseodymium, or terbium to stripuncontrolled native oxide layers on the work piece surface, as well asto control the rate of coating deposition. Typical preparative agentsfor the formation of tetravalent cerium, praseodymium, or terbiumconversion coatings are fluorides and fluorine-containing chemicals.Acidic species or other halides such as chlorides, bromides, and iodidescan be used, but are less effective than fluorides as preparativeagents.

In another optional aspect, the invention is the achievement of superiorcorrosion-resistant conversion coatings by allowing the depositedtetravalent cerium-, praseodymium-, or terbium-containing coating toreach a desired thickness and/or morphology in order to maximizeadhesion to the work piece, as well as maximizing adhesion ofsubsequently-applied paint films to the conversion coating. Ideally, thethickness of the formed tetravalent cerium, praseodymium, or terbiumconversion coating should be approximately 200 nanometers. The minimumthickness allowable for a satisfactory pinhole-free tetravalent cerium,praseodymium, or terbium conversion coating is approximately 25nanometers, and the maximum allowable thickness is approximately 10,000nanometers. The morphology of the formed conversion coating should besufficient to allow for paint films to adhere to it. A “mud crack” or“honeycomb” morphology is typical.

Accordingly, it is an object of the present invention to providenon-toxic corrosion-protection conversion coating baths based ontetravalent cerium, praseodymium, or terbium and methods of making andusing the sane. These and other objects and advantages of the presentinvention will be more fully understood from the following detaileddescription of the invention. It is noted that the scope of the claimsis defined by the recitations therein and not by the specific discussionof features and advantages set forth in the present description.

DETAILED DESCRIPTION OF THE INVENTION A) Starting Materials

Five general starting materials can be used for the conversion coatingbaths of the present invention. These include: a cerium, praseodymium,or terbium source; an oxidation source (optional); a preparation agentsource (optional); a valence stabilizer source; and additionalsolubility control agents (optional). These materials may be included asneat compounds in the conversion coating bath, or may be added to theconversion coating bath as already-prepared solutions. Furtherenhancements to the formed coating may be imparted through the use ofadditional starting materials. Foremost among these are agents toimprove the color-fastness of the coating.

1) Cerium, Praseodymium, or Terbium Source

a) Cerium Source

The cerium precursor compounds can be almost any cerium compound inwhich the cerium is in either the trivalent or tetravalent oxidationstate. Water-soluble precursors are typically used. Examples ofinorganic trivalent (“cerous”) cerium precursor compounds include, butare not restricted to: cerous nitrate, cerous sulfate, cerousperchlorate, cerous chloride, cerous fluoride, cerous bromide, cerousiodide, cerous bromate, and complex fluorides such as cerousfluosilicate, cerous fluotitanate, cerous fluozirconate, cerousfluoborate, and cerous fluoaluminate. Organometallic trivalent ceriumprecursor compounds include, but are not limited to, cerous formate,cerous acetate, cerous propionate, cerous butyrate, cerous glycolate,cerous lactate, cerous sulfonate, cerous alkyl sulfonate, cerousalkoxysulfonate, cerous aromatic sulfonate, cerous aromatoxy sulfonate,cerous sulfamate, cerous alkyl phosphates, and cerous acetylacetonate.Complex trivalent cerium precursor compounds include, but are notlimited to, ammonium cerous sulfate, ammonium cerous nitrate, ammoniumcerous oxalate, magnesium cerous nitrate, magnesium cerous sulfate,alkali cerous nitrate, and alkali cerous sulfate.

The cerium precursor may also be a compound in which the cerium isalready in the tetravalent (“ceric”) oxidation state. Examples of thesecompounds include, but are not restricted to: ceric chloride, cericfluoride, ceric perchlorate, ceric sulfate, ceric nitrate, cericacetate, ceric propionate, ceric butyrate, ammonium ceric nitrate,ammonium ceric sulfate, magnesium ceric nitrate, magnesium cericsulfate, alkali ceric nitrate, and alkali ceric sulfate.

Insoluble trivalent or tetravalent cerium compounds may be acceptable insome coating solutions, particularly if acids are used as thepreparative agent. Examples of insoluble trivalent cerium compoundsinclude cerous carbonate, cerous phosphate, cerous sulfide, cerousfluorocarbonate, cerous benzoate, cerous oxalate, cerous malonate,cerous tartrate, cerous malate, cerous citrate, cerous thiocyanate,cerous salicylate, cerous oxide, and cerous hydroxide. Examples ofinsoluble tetravalent cerium precursors are ceric hydroxide species(i.e., ceric hydroxysulfate, ceric hydroxychloride, cerichydroxynitrate, ceric hydroxyphosphate, ceric hydroxyperchlorate, andceric hydroxyacetate) with a hydroxide content of 50% or less.

It may not be necessary to add a separate cerium source for theseconversion coating solutions if a cerium-containing alloy is to betreated. The preparative agent contained within these conversion coatingformulations can dissolve some of the cerium in the substrate. This willresult in trivalent cerium ions being present in the coating solution. Asuitable oxidizer can then oxidize the trivalent cerium to the necessarytetravalent oxidation state during or after coating deposition.

b) Praseodymium Source

The tetravalent praseodymium ion (Pr⁺⁴) is an even better oxidizingspecies than Ce+⁴. It has a radius of 0.085 nanometers, carries a chargeof ⁺⁴, and has a redox potential of approximately +3.2 V. However, ithas a correspondingly lower stability both in and out of solution.Therefore, valence stabilization of this ion is needed in order to useit effectively in a conversion coating. The very large redox potentialof Pr⁺⁴ makes it prone to rapid reduction, and few materials willeffectively valence stabilize Pr⁺⁴ in a sparingly soluble complex, whichmake its routine application problematic. Tetravalent praseodymium canbe made using chemical or electrolytic oxidation, as can trivalentpraseodymium.

Praseodymium precursors can be nearly any water soluble praseodymiumcompound in which the praseodymium has a trivalent or tetravalentoxidation state. Water-soluble precursors are typically used. Inorganicpraseodymium precursor compounds include, but are not limited to,praseodymium nitrate, praseodymium sulfate, praseodymium perchlorate,praseodymium chloride, praseodymium fluoride, praseodymium bromide,praseodymium iodide, praseodymium bromate, and complex fluorides such aspraseodymium fluosilicate, praseodymium fluotitanate, praseodymiumfluozirconate, praseodymium fluoborate, and praseodymium fluoaluminate.Organometallic praseodymium precursor compounds include, but are notlimited to, praseodymium formate, praseodymium acetate, praseodymiumpropionate, praseodymium lactate, praseodymium benzenesulfonate, andpraseodymium acetylacetonate. Complex praseodymium precursor compoundsinclude, but are not limited to, ammonium praseodymium sulfate, ammoniumpraseodymium nitrate, magnesium praseodymium nitrate, magnesiumpraseodymium sulfate, alkali praseodymium nitrate, and alkalipraseodymium sulfate.

c) Terbium Source

The tetravalent terbium ion (Tb⁺⁴) is an even better oxidizing speciesthan Ce⁺⁴. It has a radius of 0.076 nanometers, carries a charge of ⁺⁴,and has a redox potential of approximately +3.2 V. However, it has acorrespondingly lower stability both in and out of solution. Therefore,valence stabilization of this ion is needed in order to use iteffectively in a conversion coating. The very large redox potential ofTb⁺⁴makes it prone to rapid reduction, and few materials willeffectively valence stabilize Tb⁺⁴ in a sparingly soluble complex, whichmake its routine application problematic. Tetravalent terbium can bemade using chemical or electrolytic oxidation, as can trivalent terbium.

Terbium precursors can be nearly any water soluble terbium compound inwhich the terbium has a trivalent or tetravalent oxidation state.Water-soluble precursors are typically used. Inorganic terbium precursorcompounds include, but are not limited to, terbium nitrate, terbiumsulfate, terbium perchlorate, terbium chloride, terbium fluoride,terbium bromide, terbium iodide, terbium bromate, and complex fluoridessuch as terbium fluosilicate, terbium fluotitanate, terbiumfluozirconate, terbium fluoborate, and terbium fluoaluminate.Organometallic terbium precursor compounds include, but are not limitedto, terbium formate, terbium acetate, terbium propionate, terbiumlactate, terbium benzenesulfonate, and terbium acetylacetonate. Complexterbium precursor compounds include, but are not limited to, ammoniumterbium sulfate, ammonium terbium nitrate, magnesium terbium nitrate,magnesium terbium sulfate, alkali terbium nitrate, and alkali terbiumsulfate.

d) Mixed Cerium; Praseodymium, and Terbium Sources

It is also possible to use mixtures of cerium, praseodymium, and/orterbium sources as feedstock for material preparation. Inclusion ofother rare earths (such as yttrium, lanthanum, or neodymium) that cannotbe oxidized to the tetravalent state is also permissible. Additionally,minerals that serve as ores for rare earths are ideal source materialsfor this application. For example, sulfuric acid is often applied torare earth ores to separate the rare earth mixtures (REM) from nativerock. If these sulfuric acid extracts were in turn to be supplied withoxidizers and valence stabilizers, source material for this applicationis achieved. Examples of rare earth-containing minerals suitable forthis application are bastnaesite [(REM)CO₃F], monazite [(REM)PO₄],xenotime [(REM)PO₄], loparite [(REM,Na,Ca)(Ti,Nb)O₃], lanthanite[(REM)₂(CO₃)₃], rhabdophane [(REM)PO₄], fergusonite [(REM)NbO₄], cebaite[Ba₃(REM)₂(CO₃)₅F₂], aeschynite [(Ca,REM)(Ti,Nb)(O,OH)₆], lucasite[(REM)Ti₂(O,OH)₆], stillwellite [(REM,Ca)BSiO₅], samarskite[(REM,Fe)₃(Nb,Ta,Ti)₅O₁₆], parisite [Ca(REM)₂(CO₃)₃F₂], gadolinite[Be₂Fe(REM)₂Si₂O₁₀], fluocerite [(REM)F₃], cerianite [(REM)O₂₋₃],churchite [(REM)PO₄), or combinations thereof.

2) Oxidation Source

Oxidizers serve two important functions within the coating: 1) they actin cooperation with the stabilizer to impede the flow of ionic speciesthrough the coating, therefore minimizing charge transport, and 2) if ascratch is formed in the coating, these oxidizing species act to repairthe breach by oxidizing the metal in the presence of water, and quicklyreforming an oxide barrier. The effectiveness of the oxidizing speciesis a function of its individual oxidation-reduction potential, with morehighly oxidized species exhibiting greater corrosion protection.

In order to provide adequate oxidation potential in the conversioncoating solution, especially if trivalent cerium, praseodymium, orterbium compounds are utilized as precursors, an oxidizing species isalso included as a starting material. Additional amounts of oxidizer maybe added to help control and maintain a desired amount of Ce⁺⁴ in theconversion coating solution by reoxidizing Ce⁺⁴ that has been reduced.Because of the high potential of the redox reaction needed to oxidizetrivalent cerium, praseodymium, or terbium to tetravalent cerium,praseodymium, or terbium, strong oxidizers must be utilized for thispurpose. These oxidizers may be gaseous, liquid, or solid in form. Solidoxidizers are typically used for this application due to ease ofhandling and reagent measurement. Other starting materials (cerium,praseodymium, or terbium source, fluoride source, stabilizer source)will frequently also be solids. Liquid oxidizers may also be used, buthandling and accurate process metering have proven difficult. Gaseousoxidizers may be the most cost effective and chemically efficient on alarge scale, but are also the most problematic due to handling andventing concerns.

Examples of oxidizers suitable for the purpose of producing andmaintaining the cerium, praseodymium, or terbium ions in the tetravalentcharge state include, but are not restricted to: peroxides and peroxocompounds (including superoxides, persulfates, perborates, pernitrates,perphosphates, percarbonates, persilicates, peraluminates, pertitanates,perzirconates, permolybdates, pertungstates, pervanadates, and organicperoxyacid derivatives), ozone, hypochlorites, chlorates, perchlorates,nitrates, nitrites, vanadates, iodates, hypobromites, chlorites,bromates, permanganates, periodates, and dissolved oxygen. Bothinorganic and organic derivatives of these compounds may be used.Typical oxidizers are peroxides, persulfates, perbenzoates, periodates,bromates, hypochlorites, and gaseous dissolved oxygen, including theoxygen content of air. In general, any inorganic, organic, orcombination species that has an oxidation potential of +1.6 V or higher(at a pH of 1) will be capable of oxidizing trivalent cerium to thetetravalent oxidation state. The formation of tetravalent praseodymiumor terbium requires higher oxidation potentials. In the presence ofsuitable valence stabilizer compounds, tetravalent praseodymium orterbium can be formed from praseodymium or terbium solutions with anoxidation potential of +2.0 V or higher (at a pH of 1).

Oxidation of the cerium, praseodymium, or terbium to the tetravalentstate may also be achieved in the conversion coating solution throughelectrolytic means. In most instances, however, this approach may not beeconomically feasible due to the large energy costs associated withelectrolytic oxidation. Chemical oxidation, such as that describedabove, currently offers the lowest-cost means to achieve oxidation ofthe cerium, praseodymium, or terbium to the tetravalent state.

It is also possible to deposit trivalent cerium, praseodymium, orterbium in a conversion coating, and then apply a second solutioncontaining an oxidizer to oxidize trivalent cerium, praseodymium, orterbium to tetravalent cerium, praseodymium, or terbium. This, however,is less typical because the percentage of deposited cerium,praseodymium, or terbium that will be in the tetravalent state will beless than if tetravalent cerium, praseodymium, or terbium were depositeddirectly.

In many of the the conversion coating solutions based on hexavalentchromium, oxidation sources are added to speed up the conversion coatingprocess. Hence, they are termed “accelerators” in the hexavalentchromium formulations. Because the application of an acid (i.e., aconversion coating solution) to an electronegative metal will result inthe formation of hydrogen gas, cathodic areas on the treated metal willbe partially blocked from further coating formation. Oxidizers(“accelerators”) act to eliminate hydrogen gas formation, therebyminimizing its barrier effect, and hence accelerating the overalldeposition rate. It is for this reason that it is also desirable to haveoxidizers in the initial conversion coating bath.

3) Preparative Agent Source

Uniform, adherent, low-defect film growth can be achieved if theconversion coat is deposited on a suitably prepared surface. Removingpre-existing “wild” native oxides is the first step to achieve theformation of high-quality conversion coatings. A preparative agent isany material that removes (dissolves and breaks up) preexisting surfaceoxides and provides a bare metal surface on which to deposit theconversion coating. The hexavalent chromium formulations term thesematerials “activators” or “surface etchants.” The breakup anddissolution of the surface oxide in solution produces a bare unprotectedmetal suited for controlled oxidation, textures the surface, andencourages precipitation of the conversion coat compounds at the metalsurface by locally raising the solution pH.

Fluoride acids and salts work especially well as preparative agents inconversion coating baths. The complex fluoride anionshexafluorozirconate (ZrF₆ ⁻²) and hexafluorotitanate (TiF₆ ⁻²) aresuperior fluoride sources for this application. Hexafluorosilicates(SiF₆ ⁻²) can be used, but they result in a reduced level of subsequentcorrosion protection. The potassium, lithium, sodium, and ammonium saltsof these anions work especially well for this application, withpotassium performing the best.

Other complex fluorides, including, but not restricted to,fluoroaluminates (e.g., AlF₆ ⁻³ or AlF₄ ⁻¹), fluoroborates (e.g., BF₄⁻¹), fluorogallates (e.g., GaF₄ ⁻¹) fluoroindates (e.g., InF₄ ⁻¹),fluorogermanates (e.g., GeF₆ ⁻²), fluorostannates (e.g., SnF₆ ⁻²),fluorophosphates (e.g., PF₆ ⁻¹), fluoroarsenates (e.g., AsF₆ ⁻¹),fluoroantimonates (e.g., SbF₆ ⁻¹), fluorobismuthates (e.g., BiF₆ ⁻¹),fluorosulfates (e.g., SF₆ ⁻²), fluoroselenates (e.g., SeF₆ ⁻²),fluorotellurates (e.g., TeF₆ ⁻² or TeOF₅ ⁻¹), fluorocuprates (e.g., CuF₃⁻¹ or CuF₄ ⁻²), fluoroargentates (e.g., AgF₃ ⁻¹ or AgF₄ ⁻²),fluorozincates (e.g., ZnF₄ ⁻²), fluorohafnates (e.g., HfF₆ ⁻²),fluorovanadates (e.g., VF₇ ⁻²), fluoroniobates (e.g., NbF₇ ⁻²),fluorotantalates (e.g., TaF₇ ⁻²), fluoromolybdates (e.g., MoF₆ ⁻³),fluorotungstates (e.g., WF₆ ⁻¹), fluoroyttrates (e.g., YF₆ ⁻³),fluorolanthanates (e.g., LaF₆ ⁻³), fluorocerates (e.g., CeF₆ ⁻³ or CeF₆⁻²), fluoromanganates (e.g., MnF₆ ⁻²), fluoroferrates (e.g., FeF₆ ⁻³),fluoronickelates (e.g., NiF₆ ⁻²), and fluorocobaltates (e.g., CoF₆ ⁻²)are also suitable fluoride sources, but these offer even less corrosionprotection than hexafluorosilicates. Water-soluble potassium, sodium,lithium, or ammonium salts of these anions are typical.

Simple inorganic fluorides such as potassium fluoride (KF), potassiumhydrogen fluoride (KHF₂), sodium fluoride (NaF), sodium hydrogenfluoride (NaHF₂), lithium fluoride (LiF), lithium hydrogen fluoride(LiHF₂), ammonium fluoride (NH₄F), ammonium hydrogen fluoride (NH₄HF₂),and even hydrofluoric acid solutions (HF) can also be used as a fluoridesource. By analogy, organic compounds that provide a ready supply ofaqueous fluoride ions will likewise serve as adequate fluoride sources.

Other halide species, such as chlorides (Cl⁻), bromides (Br), andiodides (I⁻) can also function as preparative agents, although theirefficiency in stripping the surface oxide will not be as great as thefluorides. Inorganic or organic compounds that release chloride,bromide, or iodide anions can function as preparative agents, as can anumber of complex chlorides and bromides that are similar to thosedescribed for the fluorides. By analogy, complex hexachlorozirconates(ZrCl₆ ⁻²), hexachlorotitanates (TiCl₆ ⁻²), and hexachlorosilicates(SiCl₆ ⁻²) should function better than other chloride sources, andanalogous complex bromide and iodide sources will function better thanother bromides and iodides.

Acidic species, such as nitric acid, sulfuric acid, phosphoric acid,pyrophosphoric acid, hydrochloric acid, perchloric acid, hydrobromicacid, hydriodic acid, iodic acid, periodic acid, disulfuric acid,selenic acid, telluric acid, polyphosphoric acid, cyclophosphoric acid,phytic acid, boric acid, carboxylic acids, phosphonic acids, andsulfonic acids can also function as preparative agents. Of these, nitricacid is the most useful as a preparative agent.

Acidic species based on metal salts that exhibit a pH below 7 whenplaced into solution can also be used as preparative agents. Theadvantage in the use of these species is that they can help eliminatethe need for fluoride species as preparative agents, which are regulatedin some locations. Metal salts of titanium, zirconium, niobium,tantalum, molybdenum, tungsten, vanadium, aluminum, silicon, tin,antimony, bismuth, tellurium, yttrium, and lanthanum are especiallyuseful for this process. Halides, nitrates, sulfates, perchlorates, andcarboxylates of these metals, including double salts with alkali metalsor ammonium are most suited as acidic metal salts due to their watersolubility.

Although it is less desirable, hydroxides can also function aspreparative agents. For example, under high pH conditions zinc andaluminum are known to dissolve in water, through the formation ofzincate or aluminate anions. The use of hydroxides such as sodium,potassium, lithium, or ammonium derivatives will result in this pH rise.

Changes in the concentrations of the fluoride components also hadsignificant effects upon the character of the deposited coating. It wasfound that the corrosion resistance of the formed coating was reduced ifthe fluoride concentration in solution came near or exceeded itssolubility in water. Craters form in the coating, apparently caused byexcess back etching of deposited oxides. The concentration of fluoridealso appears to influence the thickness of the formed coating. Thesubstrate metal remains bright and shiny at very low fluorideconcentrations. These effects were found to begin when the ratio offluoride ions to cerium, praseodymium, or terbium ions in the coatingsolution dropped below 0.05.

Fluoride species with different alkali metals appeared to havenegligible effect upon the coating or its corrosion resistance. The useof lithium did not result in any improvement in corrosion resistance.Changes in the fluoride's associated alkali metals (e.g., K₂ZrF₆,Na₂ZrF₆) did alter the solubility of fluoride in solution and so controlthe amount of fluoride available to etch the metal surface.

If a preparative agent is not included in the conversion coating bath,then the “wild” native oxides must be removed by some other processprior to the application of the conversion coating.

4) Valence Stabilizers

Corrosion resistance comparable to that of hexavalent chromium can beachieved by the use of valence stabilized tetravalent cerium,praseodymium, or terbium ions in the conversion coating solutions.Valence stabilization has not been recognized previously as an importantconsideration in the development of effective corrosion-inhibitingconversion coats. A variety of inorganic and organic stabilizers areavailable that can control such properties as solubility, mobility, ionexchange, and binder compatibility. The stabilizer complex can also actas an ion-exchange host and/or trap for alkali or halide ions insolution.

Cerium, praseodymium, and terbium are effective as oxidation corrosioninhibitors if they can be supplied in sufficient quantities in thetetravalent charge state when brought into contact with unprotected baremetal. The Ce⁺⁴ ionic radius of 0.087 nanometers is larger than the0.044 nanometers of the hexavalent chromium ion, and so it will have acorrespondingly lower charge density (electrostatic field) per ion. ThePr⁺⁴ ionic radius of 0.085 nanometers and Tb⁺⁴ ionic radius of 0.076nanometers are also larger than hexavalent chromium.

As noted in the Summary of the Invention, the valence stabilizer servesa number of important functions in the establishment of a successfulconversion coating. First, the valence stabilizer, when used withtetravalent cerium, praseodymium, or terbium, results in a “sparinglysoluble” Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-valence stabilizer complex. Although theexact solubility of this complex can be slightly modified through theincorporation of different cations or anions (either through thedissolution of the coated metal, or the subsequent treatment byadditional solubility control agents), appreciable corrosion inhibitionwill be observed if the tetravalent cerium, praseodymium, or terbium isincorporated in the conversion coating as a Ce⁺⁴-, Pr⁺⁴-, orTb⁺⁴-stabilizer complex that exhibits a solubility in water of betweenabout 5×10⁻⁵ moles per liter and about 5×10⁻² moles per liter ofavailable Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴. Therefore, any material (inorganic ororganic) in the coating bath that complexes with tetravalent cerium,praseodymium, or terbium and results in the formation of a Ce⁺⁴-, Pr⁺⁴-,or Tb⁺⁴-containing complex, which exhibits solubilities within or nearthis solubility range, can serve as a valence stabilizer for tetravalentcerium, praseodymium, or terbium.

Conversion coatings which incorporate stabilized tetravalent cerium,praseodymium, or terbium compounds that fall outside this particularsolubility range may exhibit some degree of corrosion inhibition and maybe effective conversion coatings under certain circumstances. Althoughnot as effective as those compounds within the optimum solubility range,compositions with solubilities as high as 5×10⁻¹ moles per liter or aslow as 1×10⁻⁵ moles per liter of tetravalent cerium, praseodymium, orterbium, at standard temperature and pressure (about 25° C. and about760 Torr), exhibited some corrosion resistance. For example, insituations where the substrate metal pieces are exposed to environmentswhich require much more immediate corrosion exposure (e.g., suddenimmersion in seawater), adequate corrosion protection can be achievedthrough the formation of a tetravalent cerium, praseodymium, or terbiumcompound which exhibits a higher solubility in water (e.g., 5×10⁻¹ to5×10⁻³ moles/liter tetravalent cerium, praseodymium, or terbium). Inthis way, a more “immediate” release of protective tetravalent cerium,praseodymium, or terbium ions can be achieved, although the tetravalentcerium, praseodymium, or terbium will be depleted faster from thecoating. Tetravalent cerium, praseodymium, or terbium solubilities thatare lower than this optimum range (e.g., 1×10⁻⁵ to 1×10⁻³ moles/liter oftetravalent cerium, praseodymium, or terbium) may be desirable for somesituations (e.g., in nearly pure water with low aeration rates).However, compounds that exhibit solubilities far outside the targetrange are unlikely to be effective corrosion inhibitors.

The solubility characteristics of the tetravalent cerium, praseodymium,or terbium in the conversion coatings is controlled with stabilizermaterials that form compounds within the desired solubility range. Theexact solubility will be strongly dependent on the application of theconversion coating and net aqueous solubility of overlying paints andcoatings.

The formation of conversion coatings with the proper release rate ofCe⁺⁴, Pr⁺⁴, or Tb⁺⁴ ions is problematic because of the instability ofCe⁺⁴ and especially Pr⁺⁴ or Tb⁺⁴ out of solution. Tetravalent ceriumcompounds, such as ammonium ceric nitrate, and ammonium ceric sulfateare generally too soluble to serve as effective corrosion inhibitors ifincorporated into a conversion coating. Oxides and hydroxides of Ce⁺⁴are often too insoluble in water to serve effectively as corrosioninhibitors in a conversion coating. For example, ceric oxide (CeO₂) isso insoluble that its solubility has never been accurately determined.The more soluble “hydrated” ceric oxide [ceric hydroxide-Ce(OH)₄] isreported to exhibit a solubility product in water between 4.2×10⁻⁵¹ and1.5×10⁻⁵¹, resulting in a cerium solubility of approximately 5×10⁻¹²moles/liter Ce⁺⁴ (see Tarayan, V. M. and Eliazyan, L. A., Izvest. Akad.Nauk Armyan. S. S. R., Ser. Khim. Nauk 10: 189-93, (1957) in General andPhysical Chemistry, vol. 2, col. 9722 (1958) (Abstract)). Similarly,tetravalent praseodymium oxide (Pr₆O₁₁) is reported to exhibitsolubility in water of 6.5×10⁻⁷ moles/liter Pr⁺⁴ (see Busch, W., Z.anorg. allgem. Chem. 161: 161-79 (1927) in Chemical Abstracts, vol. 21,p. 2412 (Abstract)). For these low solubility compounds, the releaserates of Ce⁺⁴ or Pr⁺⁴ are too low to compare adequately to Cr⁺⁶ from thestate-of-the-art coatings.

The solution to providing a useful source of tetravalent cerium,praseodymium, or terbium at a metal surface is the creation of asparingly soluble compound in which the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion isshielded from premature reduction during and after conversion coatingformation. The assembly of a protective shell around the highly chargedCe⁺⁴, Pr⁺⁴, or Tb⁺⁴ and its associated oxygen and hydroxyl species canhelp control the rate at which the cerium, praseodymium, or terbium isreduced and its oxygen is released. Proper selection of materials forforming the protective shell will allow solubility tailoring of theentire assembly to its intended application environment. Valencestabilizers are materials that, when assembled, modify the rate ofreduction and the solubility of the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ions.

The electrostatic character of the complex should also be considered increating a Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ stabilizer complex with optimal corrosionresistance. Valence stabilizers can also contribute to the developmentof a substantial electrostatic double layer. An electrostatic doublelayer of polar or charged species such as hydronium (H₃O⁺) or hydroxide(OH⁻) ions surrounding the stabilized cerium, praseodymium, or terbiumcomplex will help control cerium, praseodymium, or terbium reduction andsolubility and enhance the barrier properties of the conversion coating.Valence stabilizers which form sparingly soluble cerium, praseodymium,or terbium complexes with enhanced electrostatic double layers willmaximize the corrosion-inhibiting character of the conversion coating.

The tetravalent cerium, praseodymium, or terbium ions are larger thanthe hexavalent chromium ion, with less charge density over the surfaceof the ion. Therefore, the valence stabilizers for Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴must be more efficient in the establishment of dipole moments than thevalence stabilizers typically used for hexavalent chromium so thatcomparable corrosion resistance can be achieved in relation to thestate-of-the-art Cr⁺⁶ compositions. Valence stabilizers which have acomparable dipole moment to the Cr⁺⁶ stabilizers, or which exhibit evenless of a dipole moment than the Cr⁺⁶ stabilizers can also function asvalence stabilizers, but the resultant corrosion resistance of theconversion coatings will, in all probability, be less than for thecurrent commercial hexavalent chromium-based conversion coatings.

Large spheres of hydration around corrosion inhibitors can act aselectrostatic and physical barriers to the passage of large corrosiveions such as Cl⁻ and SO₄ ⁻² through the coating to the metal surface.The size of the electrostatic double layer is a function of theelectrostatic potential at the complex surface and is inverselyproportional to the ionic strength of the surrounding solution.Compounds that can carry a charge, have a natural electrostatic dipole,or can have a dipole induced, will likely form an electrostatic doublelayer in aqueous solution. However, these compounds do not normally actas corrosion inhibitors because they have not been optimized for thatpurpose.

These facts are relevant when tetravalent cerium's propensity forattracting hydroxide species such as OH⁻ in solution is considered.While a tetravalent cerium ion surrounded solely by OH⁻ [i.e., Ce(OH)₄]may have a slight degree of aqueous solubility, the much lower chargedensity (electrostatic field) that is exhibited by Ce⁺⁴ (coupled withthe muting effect of the surrounding OH⁻ ions) implies that theelectrostatic double layer formed around this assemblage will be small.If fewer hydroxide species surround the tetravalent cerium ion [i.e.,Ce(OH)₂ ²⁺ or Ce(OH)³⁺], the electrostatic double layer around theseionic assemblages is increased, which will result in increased corrosionprotection. Tetravalent cerium surrounded by no hydroxide species offersthe highest degree of corrosion protection.

A simple laboratory experiment confirms this effect. If tetravalentcerium hydroxide [Ce(OH)₄] is placed into deionized water of pH 7, onlya minor pH change will be observed, implying that the ionic attractionof this species for hydronium or hydroxide species is minimal. However,if icosahedral Ce(NO₃)₆ ²⁻ (note that this ion contains no hydroxide) isplaced into deionized water of pH 7, a quite remarkable pH drop to −1can be observed. The released tetravalent cerium ions will scavengevirtually all of the available OH⁻ ions in solution (possibly evendegrading H₂O itself to obtain OH⁻), resulting in this dramatic pH drop.

These factors account for the lower corrosion performance of the hydrousoxides and hydroxides formed in many of the prior art references.Because the electrostatic double layers of hydrated cerium oxides andhydroxides are so small, their ability to impede the progress ofcorroding species is very low, even in the event that a minorconcentration of these complexes become soluble. Unlike the other knowncorrosion-resistant components described in the art, which extol theformation of hydrous cerium oxides and hydroxides, this inventionrecognizes that these species result in lower corrosion performance inside-by-side tests. In fact, any oxo- or hydroxo- coordination greaterthan 50% on the tetravalent cerium ions (i.e., greater than Ce(OH)₂ ²⁺or CeO²⁺) is objectionable. It is also for this reason that thisinvention does not promote the use of wide band hydroxide or oxide asvalence stabilizers for tetravalent cerium.

Optionally, the incorporation of the valence stabilizer (inorganic ororganic) should result in the formation of a Ce⁺⁴-, Pr⁺⁴-, orTb⁺⁴-valence stabilizer compound which exhibits ion exchange behaviortowards alkali ions. As noted in the Summary of the Invention, this isnot a requirement of the Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-valence stabilizercomplex, but it is a desirable characteristic for enhanced corrosionresistance. Some existing state-of-the-art chromium systems exhibit thisphenomena, but conversion coating compounds that do not exhibit thisphenomena have been successfully demonstrated to inhibit corrosiveattack.

Rare earth coordination chemistry, which has been the subject ofnumerous scientific studies for almost 100 years, identifies chemicalbinding preferences, structure stability, and physical properties of theresulting compounds. Producing effective Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-valencestabilizer complexes requires understanding the electrostatic andstructural influence of candidate species on the complex. Stabilizerscan be designed that result in cerium, praseodymium, or terbiumcompounds with the necessary physical, electrical, and chemicalproperties to form corrosion inhibitors with this information. Propertytailoring can also take place through selection of specific anions orcations bound to the Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-valence stabilizercoordination complex.

The functional anatomy of inorganic stabilizers is simple because of thelimited number of atoms and structural arrangements involved in theirformation. The anatomy of organic stabilizers is not as simple. Anorganically stabilized cerium, praseodymium, or terbium complex may haveone or more organic ligands that may have one or more bonding sites thatcan interact with the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion/oxide cluster. The bondinggroups can be the same or different atoms or functional groups on anindividual or a variety of ligands. An organic stabilizer ligand can bemodified in an unlimited number of ways to tailor its physical behaviorwith respect to such properties as chemical reactivity, solubility,electrostatic and polar character, and functional behavior.

The stability of the Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-valence stabilizer complex isstrongly influenced by the charge, polarity sign, and degree ofpolarizability of specific binding sites. Factors influencing compoundstability include: 1) ion-pair interactions for charged ligands andCe⁺⁴, Pr⁺⁴, or Tb⁺⁴, 2) ion-dipole and ion-induced dipole interactionsfor neutral ligands, 3) hydrogen bonding, and 4) the hard-soft acid-base(HSAB) rules convention of coordination chemistry. HSAB rules helpidentify functional groups on ligands that might be effective as bindingsites. Optimum binding for organic valence stabilizers to Ce⁺⁴, Pr⁺⁴, orTb⁺⁴ will involve ligands with hard bonding species such as those thatcontain oxygen or nitrogen. Certain coordination complexes of the softbases sulfur or phosphorus are also effective for binding with Ce⁺⁴,Pr⁺⁴, or Tb⁺⁴. HSAB rules can also help identify groups that mightprovide a degree of polarization to the stabilizer because of theirlarge dipole moments.

The nature of bonding between the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion/oxide clusterand the stabilizer ligand can be altered by using a substituent group tomodify the stabilizer. Specific interactions between the ligand andCe⁺⁴, Pr⁺⁴, or Tb⁺⁴ can be tailored by substituent group selection,coupled with altering the size or geometry of the complexing ligand. Forexample, some substituent groups have large dipole moments associatedwith them, which will increase the electrostatic barrier layersassociated with the cerium/valence stabilizer complexes. These include:ketones (═C═O), thioketones (═C═S), amides (—C[═O]—NR₂), thioamides(—C[═S]—NR₂), nitriles or cyano groups (—CN), isocyanides (—NC), nitrosogroups (—N═O), thionitroso groups (—N═S), nitro groups (—NO₂), azidogroups (—N₃), cyanamide or cyanonitrene groups (═N—CN), cyanate groups(—O—CN), isocyanate groups (—N═C═O), thiocyanate groups (—S—CN),isothiocyanate groups (—N═C═S), nitrosamine groups (═N—N═O),thionitrosamine groups (═N—N═S), nitramine groups (═N—NO₂),thionitramine groups (═N—NS₂), carbonylnitrene groups (—CO—N),thiocarbonylnitrene groups (—CS—N), sulfenyl halides (—S—X), sulfoxides(═S═O), sulfones (═S[═O]₂), sulfinyl groups (—N═S═O), thiosulfinylgroups (—N═S═S), sulfenyl thiocyanato groups (—S—S—CN), sulfenyl cyanatogroups (—S—O—CN), sulfodiimine groups (═S[═NH]₂), sulfur dihaloimidogroups (—N═SX₂), sulfur oxide dihaloimido groups (—N═S[═O]X₂),aminosulfur oxide trihalide groups (═N—S[═O]X₃), sulfonyl azide groups(—S[═)]₂N₃), sulfonyl thiocyanate groups (—S[═O]₂SCN], sulfonyl cyanategroups (—S[═O]₂OCN), sulfonyl cyanide groups (—S[═O]₂CN), halosulfonategroups (—S[═O]₂OX), phosphonyl thiocyanate groups (—P[═O]OHSCN),phosphonyl cyanate groups (—P[═O]OHOCN), and phosphonyl cyanide groups(—P[═O]OHCN). The polarization of the Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-stabilizercan therefore be optimized via evaluation of the effect of ligand typeand substituents. The influence of the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion on theaqueous solution outside of, or external to, the valence stabilizershell (or hydration sphere) may play an important role in thecomplexation properties of a given ligand. It will also control thediameter of the hydration shell around the Ce⁺⁴-, Pr⁺⁴-, orTb⁺⁴-stabilizer complex.

The number of binding sites available on the complexing ligand isimportant to the resulting Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-stabilizer'sproperties. Several ligands are needed to stabilize Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴effectively if the chosen ligand has only one binding site. Six NO₃ ⁻ligands are needed to icosahedradrally coordinate Ce⁺⁴ in ahexanitratocerate(IV) complex because NO₃ ⁻ has only one binding site.Bulky ligands with only one binding site, like pyridine, can besterically hindered from packing tightly around the ion, which willresult in decreased complex stability. Conversely, macrocyclic organicand polymeric inorganic ligands may have many suitable binding sites.However, instability will result if a Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion is notcompletely embraced by all of the multiple macromolecular bonding siteson the ligand. For example, if a macromolecule surrounding the Ce⁺⁴ ionhas an insufficient number of binding sites available for chargebalance, then the Ce⁺⁴-stabilizer complex will be much less stable thanwith a macromolecule that contains an adequate number of sites.

The physical geometry of the binding sites is important to the stabilityof the Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-stabilizer complex. The influence of sitegeometry becomes evident when the solvation shell of a Ce⁺⁴, Pr⁺⁴, orTb⁺⁴ ion is replaced by the ligand donor atoms as when conversioncoatings are formed. The number of available ligand binding sites shouldbe at least equal to the standard coordination number of the Ce⁺⁴, Pr⁺⁴,or Tb⁺⁴ ion. The balance between solvation of the ligand and Ce⁺⁴, Pr⁺⁴,or Tb⁴ and their complexation where Ce⁺⁴, Pr⁺⁴, or Tb⁴ a specific ligandis important in maintaining stability. Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-ligandattraction increases with the number of available binding sites on theligand. However, with an increasing number of binding sites, site-siterepulsions will also increase, resulting in lower stability.

The Ce⁺⁴, Pr⁺⁴, and Tb⁺⁴ ions generally favor complexation in theicosahedral (coordination number 12) or octahedral (coordination number6) arrangements. However, these ions will occasionally be found in asquare antiprismatic, cubic, or complex arrangement. Valence stabilizers(and stabilizer combinations) should be selected with the goal ofachieving these coordinations.

Inorganic materials that tend to “polymerize” and form octahedra oricosahedra (or a combination thereof) around ions such as Ce⁺⁴, Pr⁺⁴, orTb⁺⁴ are termed isopolyanions, and their resultant complexes with Ce⁺⁴,Pr⁺⁴, or Tb⁺⁴ are termed heteropolyanions or heteropolymetallates. Thispolymerization of the inorganic valence stabilizer species results instacks of octahedra or icosahedra with central cavities which canaccommodate at least one Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion, thereby stabilizingit.

Valence stabilizers and combinations of stabilizers can be manipulatedby the selection of “shaping groups” and heteroatoms positioned at thebinding site. Inorganic valence stabilizers are typicallyoxygen-containing coordination compounds. Saturated organic chains canform flexible ligands that wrap around Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ and canenhance its stability. Unsaturated organics typically have less freedomto bend and contort and are less likely to be able to wrap around theCe⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion. The addition of substituents onto an organicligand may further restrict its freedom to flex.

The actual size of the valence stabilizer complex situated around theCe⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion has an important role in solubility control.Solubility of the complex scales roughly with the inverse of itsphysical diameter. Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ and their layer of negativelycharged hydroxyl ions is small and results in its high degree of aqueoussolubility. The field strength of the complex also scales with theinverse of its physical diameter. Large complexes with an optimal degreeof solubility will not necessarily be ideal with respect to the size ofthe electrostatic double layer. The size of the ligand is thereforebalanced against the desired electrical properties.

The addition (or subtraction) of functional groups on organic valencestabilizers can be used to modify the solubility of the formed Ce⁺⁴,Pr⁺⁴, or Tb⁺⁴/valence stabilizer species. For example, the addition ofsulfonated groups (—SO₃ ⁻) to organic valence stabilizers willsignificantly increase the solubility in water. Other substituent groupsthat will increase the solubility in water include: carboxyl groups(—CO₂—), hydroxyl groups (—OH), ester groups (—CO₃—), carbonyl groups(═C═O), amine groups (—NH₂), nitrosamine groups (═N—N═O),carbonylnitrene groups (—CO—N), sulfoxide groups (═S═O), sulfone groups(═S[═O]₂), sulfinyl groups (—N═S═O), sulfodiimines (═S[═NH]₂), sulfonylhalide groups (—S[═O]₂X), sulfonamide groups (—S[═O]₂NH₂),monohalosulfonamide groups (—S[═O]₂NHX), dihalosulfonamide groups(—S[═O]₂MX₂), halosulfonate groups (—S[═O]₂OX), halosulfonate amidegroups (═N—S[═O]₂X), aminosulfonate groups (═N—S[═O]₂OH),iminodisulfonate groups (—N[SO₃ ⁻]₂), phosphonate groups (—PO₃ ⁻²),phosphonamide groups (—PO₂NH₂ ⁻), phosphondiamide groups (—PO[NH₂]₂),aminophosphonate groups (═N—PO₃ ⁻²), and iminodiphosphonate groups(—N[PO₃ ⁻²]₂). Conversely, the addition of nitro groups (—NO₂),perfluoroalkyl groups (—C_(x)F_(2X+1)), perchloroalkyl groups(—C_(x)Cl_(2x+1)), nitramine groups (═N—NO₂), thioketone groups (═C═S),sulfenyl halide groups (—S—X), or sulfur dihaloimide groups (—N═SX₂) toorganic valence stabilizers will decrease the solubility in water. Inthis way, the solubility characteristics of valence stabilizers can betailored to meet specific needs.

The physical, chemical, and electrostatic requirements for the design ofeffective Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-stabilizer complexes results in lists ofstabilizers that may be divided into wide band or narrow band stabilizerclasses. The compounds listed here are general guides for the initialselection of a coordination compound and do not represent a complete orfinal list. New organic and inorganic compounds are continuously beingdeveloped, compound toxicity limits can change, and some currentlyavailable compounds may have been overlooked. Tailoring substituentgroups and the selection of cations or anions for charge balance caninfluence whether a particular Ce⁺⁴-, Pr⁺⁴-, or Tb⁺⁴-stabilizer complexwill have a wide band or narrow band character.

Valence stabilizers for tetravalent cerium, praseodymium, or terbiumthat embody the desirable characteristics of stabilizers as describedabove are typical when designing a conversion coating for maximumeffectiveness. These “wide band” stabilizers result in the formation ofcompounds that provide significant corrosion resistance when used withtetravalent cerium, praseodymium, or terbium. “Narrow band” valencestabilizers result in satisfactory conversion coatings only underlimited applications. Wide band conversion coatings for general purposeapplications and narrow band conversion coatings for specific uses havebeen identified and developed. In general, valence stabilizers that formcerium, praseodymium, or terbium complexes which exhibit the necessaryphysical properties of stability, solubility, and polarization may beachieved with both inorganic and organic valence stabilizers. Ionexchange behavior can also be achieved with both inorganic and organiccoordination compounds.

Because of the much higher oxidation-reduction potential associated withPr⁺⁴ and Tb⁺⁴, the choice of suitable valence stabilizers for thesespecies is much more limited and will be dealt with in a separatesection (4f). Sections 4a through 4e describe suitable stabilizers forCe⁺⁴.

4a) Wide Band Inorganic Valence Stabilizers for Ce⁺⁴

Wide band inorganic stabilizers are formed around the Ce⁺⁴ ion bypolymerizing in the conversion coating solution near the metal surfacebeing treated. Acidic coating solutions can become basic near the metalsurface where precipitation of the cerium-stabilizer complex occursduring the coating process. Inorganic wide band valence stabilizers forCe⁺⁴ include, but are not limited to: molybdates (Mo⁺⁶, Mo⁺⁵, or Mo⁺⁴,for example [Ce⁺⁴Mo₁₂O₄₂]⁸⁻, [Ce⁺⁴Mo₇O₂₄]²⁻, and [Ce⁺⁴ ₂Mo₁₄O₄₈]⁴⁻);tungstates (W⁺⁶, W³⁰ ⁵, or W⁺⁴, for example [Ce⁺⁴W₁₂O₄₂]⁸⁻,[Ce⁺⁴W₈O₂₈]⁴⁻, and [Ce⁺⁴W₁₀O₃₅]⁶⁻); vanadates (V⁺⁵ or V⁺⁴, for example[Ce⁺⁴V₁₈O₅₁]⁸⁻); niobates (Nb⁺⁵ or Nb⁺⁴, for example[Ce⁺⁴Nb₂O₆(OH)₄]²⁻); tantalates (Ta⁺⁵ or Ta⁺⁴, for example[Ce⁺⁴Ta₂O₆(OH)₄]²⁻); tellurates (Te⁺⁶ or Te⁺⁴, for example Ce⁺⁴(TeO₄)₂);periodates (I⁺⁷, for example [Ce⁺⁴IO₆]¹⁻); iodates (I⁺⁵, for exampleCe⁺⁴(IO₃)₄); carbonates (C⁺⁴, for example [Ce⁺⁴(CO₃)₅]⁶⁻); antimonates(Sb⁺⁵ or Sb⁺³); stannates (Sn⁺⁴); phosphates (P⁺⁵, for example Ce⁺⁴₃(PO₄)₄, Ce⁺⁴(HPO₄)₂, Ce⁺⁴P₂O₇, and [Ce⁺⁴(P₂O₇)₂]⁴⁻); nitrates (N⁺⁵, forexample [Ce⁺⁴(NO₃)₆]²⁻); bromates (Br⁺⁵, for example Ce⁺⁴(BrO₃)₄); andsulfates (S⁺⁶, for example [Ce⁺⁴(SO₄)₄]⁴⁻). Many of these inorganicsform octahedral or icosahedral heteropolymetallate structures onprecipitation from solution. For example, tellurate ions begin topolymerize in solution near pH 5 and will complex with Ce⁺⁴ ions nearthe metal substrate as solution pH increases. The exact chemical natureof these valence stabilizers (i.e., chemical formulation and valencestate of the atom in the center of the icosahedra or octahedra) ishighly dependent upon the specific pH and redox conditions.

The stability of the heteropolymetallates is a function of compositionand structure. The relatively unstable Ce⁺⁴ ion is protected andstabilized within the surrounding octahedral or icosahedral groups,although specific configurations of the heteropolymetallate anionsdiffer from stabilizer to stabilizer (i.e., from molybdate to periodateto carbonate).

The dimensions of the octahedra and icosahedra are controlled by thesize of the heteroatom (e.g., Mo, W, Te) around which they areassembled. A Ce⁺⁴ ion trapped by the precipitation of theseheteropolymetallates and its resulting “ion within a cage” structure canexhibit an even greater apparent volume due to the development of alarge electrostatic double layer. This will influence both the valencestabilization of the Ce⁺⁴ as well as the solubility of the assembledcomplex. These compounds are also reported to be excellent ion exchangeagents for alkali ions.

This caging structure serves to lower the solubility of the Ce⁺⁴ becausethe chemical elements typically associated with these valencestabilizers (e.g., I, Te, Mo, W) are often inherently less soluble inwater than Ce⁺⁴. These materials can also establish oriented dipoleswith the interior Ce⁺⁴ ion, thereby forming the desired barrier layers(e.g., of hydronium ions), much as ferricyanide or molybdate probablycontributes to the hexavalent chromium systems. Finally, the elementsassociated with these valence stabilizers themselves can contain highvalence ions, such as V⁺⁵, Te⁺⁶, or Mo⁺⁶, which will also serve somewhatin corrosion protection, although not to the degree of Ce⁺⁴, due totheir lower redox potential.

Water-soluble precursors for the formation of these valence stabilizersare desirable in order to ensure that sufficient material is availablefor coating deposition from aqueous solutions. Identification ofsuitable water-soluble precursors may be difficult, since many of theelements associated with these valence stabilizers (e.g., Mo, W, Te,etc.) do not typically form water-soluble compounds (hence theirbeneficial use as a valence stabilizer). Representative examples ofsuitable precursors for “wide band” inorganic valence stabilizers arelisted in Table 6.

The solubilities given in Table 6 are usually for the simplest salts ofeach compound. More complex, partially “polymerized” salts for eachcompound (e.g., para- or meta-polymorphs) can also be used asprecursors, although these polymorphs typically exhibit slightly lowersolubilities in water than the simple salts. Peroxo-salts of thesecompounds, especially percarbonates, permolybdates, pertungstates,pertitanates, and pervanadates can also be utilized as precursors.Formation of the chosen heteropolymetallates from precursors such as thefluorides, chlorides, bromides, nitrates, and perchlorates (e.g., SnCl₄to form heterostannates, and SbF₅ to form heteroantimonates) proved tobe difficult, but may be acceptable under certain circumstances.

Ce⁺⁴ stabilized with a heteropolymolybdate complex is an example of awide band inorganically stabilized cerium complex. This complex is verystable and provides significant corrosion protection when it is used asa conversion coating. The size of the cavity developed at the center ofa ligand with three or more bonding sites is important. A cavity that istoo large or too small will tend to be less stable and less effective inuse as a corrosion inhibitor.

The valence stabilizer can be a cross between two or more of thewide-band inorganic valence stabilizers listed above. For example, insome instances it may be desirable to form a valence stabilizer out of aperiodate and a molybdate. During the coating process, both of thesematerials will polymerize to form a mixed periodate/molybdate valencestabilizer out of the conversion coating solution.

4b) Wide Band Organic Valence Stabilizers for Ce⁺⁴

A variety of organic compounds meet the criteria to be typical valencestabilizers for Ce⁺⁴. These coordination ligands produce Ce⁺⁴ valencestabilized complexes which fulfill the general requirements of a Ce⁺⁴conversion coating material. Organic compounds can be very effectivecerium stabilizers and provide the greatest degree of freedom indesigning new stabilizer species with new functionalities. There aremany more possible organic valence stabilizer species than inorganicvalence stabilizers because of the large number of organic compounds andfunctionalities which exist. Some of the typical organic valencestabilizer species are listed in Table 1 below.

The number of wide band (and narrow band) organic compounds that areacceptable as valence stabilizers for tetravalent cerium is limited.Common organic compounds such as alcohols, aldehydes, ketones, esters,ethers, alkyl or aromatic halides, most carboxylic acids, anhydrides,phenols, sulfonic acids, phosphonic acids, carbohydrates, waxes, fats,sugars, and oils are not as effective as the structural types describedin the Tables herein to stabilize the tetravalent cerium ion. At best,some of the organic types described in these Tables may presently beused for other industrial applications, but their incorporation intocorrosion-inhibiting blends to stabilize tetravalent cerium hasheretofore been unrecognized.

The choice of substituent functional groups on these general classes ofvalence stabilizers will affect the physicochemical properties of theCe⁺⁴-containing complex and the corrosion resistance achieved using thatcomplex. For example, the addition of —NH₂, or ═O substituents increasesthe net polarization of the overall Ce⁺⁴-valence stabilizer complex, butthis will also increase its water solubility. Careful molecular designof Ce⁺⁴ complexes is necessary to achieve desired performancecharacteristics.

In general, the bonding atoms in typical organic valence stabilizers areoxygen or nitrogen, with sulfur or phosphorus being acceptable in somecircumstances. Sulfur or phosphorus are complexed with Ce⁺⁴ mostfrequently in association with oxygen. Bonding atoms such as carbon,silicon, tin, arsenic, selenium, and antimony are much less desirabledue to problems with valence stability, toxicity, or solubility. Thesevalence stabilizers all serve to stabilize the Ce⁺⁴ ion within asparingly soluble complex that can exhibit a polar character in aqueoussolution.

TABLE 1 Wide Band Organic Valence Stabilizers for the Ce⁺⁴ Ion GeneralStructural Name (Type of Organic) Structural Representation N ValenceStabilizer #1: NH₃, NH₂R, NHR₂, and NR₃ where R Monoamines (NMonodentates) represents H or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N Valence Stabilizer#2: R′—N—R—N—R′′, where R, R′, and R′′ represent H Diamines (N—NBidentates) or any organic functional group wherein the number of carbonatoms ranges from 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #3:R—N—R′—N—R′′—N—R′′′, where R, R′, R′′, and R′′′ Triamines (either N—NBidentates or N—N represent H or any organic functional groupTridentates) wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #4:R—N—R′—N—R′′—N—R′′′—N—R′′′′, where R, R′, R′′, Tetramines (N—NBidentates, N—N R′′′, and R′′′′ represent H or any organic Tridentates,or N—N Tetradentates) functional group wherein the number of carbonatoms ranges from 0 to 40, optionally having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #5:R—N—R′—N—R′′—N—R′′′—N—R′′′′—N—R′′′′′, where R, Pentamines (N—NBidentates, N—N R′, R′′, R′′′, R′′′′, and R′′′′′ represent H or anyTridentates, or N—N Tetradentates) organic functional group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N Valence Stabilizer#6: R—N—R′—N—R′′—N—R′′′—N—R′′′′—N—R′′′′′—N—R′′′′′′, Hexamines (N—NBidentates, N—N where R, R′, R′′, R′′′, R′′′′, R′′′′′, and R′′′′′′Tridentates, N—N Tetradentates, or N—N represent H or any organicfunctional group Hexadentates) wherein the number of carbon atoms rangesfrom 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #7: Fivemembered heterocyclic ring containing Five-Membered Heterocyclic Ringsone, two, three, or four nitrogen atoms, all of containing One, Two,Three, or Four which may or may not function as binding sites. NitrogenAtoms wherein at least one Can include other ring systems bound to thisNitrogen Atom is a Binding Site (N heterocyclic ring, but they do notcoordinate Monodentates or N—N Bidentates) with the stabilized, highvalence metal ion. Ring can also contain O, S, or P atoms. This 5-membered ring and/or attached, uncoordinating rings may or may not havehalogen or polarizing or water-insolubilizing/solubilizing groupsattached. N Valence Stabilizer #8: Six membered heterocyclic ringcontaining one, Six-Membered Heterocyclic Rings two, three, or fournitrogen atoms, all of which containing One, Two, Three, or Four may ormay not function as binding sites. Can Nitrogen Atoms wherein at leastone include other ring systems bound to this Nitrogen Atom is a BindingSite (N heterocyclic ring, but they do not coordinate Monodentates orN—N Bidentates) with the stabilized, high valence metal ion. Ring canalso contain O, S, or P atoms. This 6- membered ring and/or attached,uncoordinating rings may or may not have halogen or polarizing orwater-insolubilizing/solubilizing groups attached. N Valence Stabilizer#9: Five membered heterocyclic ring(s) containing Five-MemberedHeterocyclic Rings one, two, three, or four nitrogen atoms. Incontaining One, Two, Three, or Four addition, ligand contains additionalnitrogen- Nitrogen Atoms and having at least one containing substituents(usually amines) that additional Nitrogen Atom Binding Site notconstitute N binding sites. Can include other in a Ring (N Monodentates,N—N ring systems bound to the heterocyclic ring or to Bidentates, NTridentates, N—N the N-containing substituent, but they do notTetradentates, or N—N Hexadentates) coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. This5-membered ring(s) and/or attached, uncoordinating rings and/or N-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N Valence Stabilizer#10: Six membered heterocyclic ring(s) containing Six-MemberedHeterocyclic Rings one, two, three, or four nitrogen atoms. Incontaining One, Two, Three, or Four addition, ligand contains additionalnitrogen- Nitrogen Atoms at least one additional containing substituents(usually amines) that Nitrogen Atom Binding Site not in a Ringconstitute N binding sites. Can include other (N Monodentates, N—NBidentates, N—N ring systems bound to the heterocyclic ring or toTridentates, N—N Tetradentates, or N—N the N-containing substituent, butthey do not Hexadentates) coordinate with the stabilized, high valencemetal ion. Ring(s) can also contain O, S, or P atoms. This 6-memberedring(s) and/or attached, uncoordinating rings and/or N- containingsubstituent(s) may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. N Valence Stabilizer #11:Five membered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one, two, three, or four nitrogen atoms. In containing One, Two,Three, or Four addition, ligand contains additional nitrogen- NitrogenAtoms at least one additional containing rings that constitute N bindingsites. Nitrogen Atom Binding Site in a Separate Can include other ringsystems bound to the N- Ring (N Monodentates, N—N Bidentates, N—Ncontaining heterocyclic rings, but they do not Tridentates, N—NTetradentates) coordinate with the stabilized, high valence metal ion.Ring(s) can also contain O, S, or P atoms. This 5-membered ring(s)and/or additional N-containing ring(s) and/or attached, uncoordinatingrings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. N Valence Stabilizer #12:Six membered heterocyclic ring(s) containing Six-Membered HeterocyclicRings one, two, three, or four nitrogen atoms. In containing One, Two,Three, or Four addition, ligand contains additional nitrogen- NitrogenAtoms at least one additional containing rings that constitute N bindingsites. Nitrogen Atom Binding Site in a Separate Can include other ringsystems bound to the N- Ring (N Monodentates, N—N Bidentates, N—Ncontaining heterocyclic rings, but they do not Tridentates, N—NTetradentates) coordinate with the stabilized, high valence metal ion.Ring(s) can also contain O, S, or P atoms. This 6-membered ring(s)and/or additional N-containing ring(s) and/or attached, uncoordinatingrings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. N Valence Stabilizer #13:Macrocyclic ligands containing two, three, four, Two-, Three-, Four-,Six-, Eight-, and Ten- six, eight, or ten nitrogen binding sites toMembered Macrocyclics, Macrobicyclics, valence stabilize the centralmetal ion. Can and Macropolycyclics (including include other hydrocarbonor ring systems Catapinands, Cryptands, Cyclidenes, and bound to thismacrocyclic ligand, but they do Sepulchrates) wherein all Binding Sitesare not coordinate with the stabilized, high valence composed ofNitrogen (usually amine or metal ion. This ligand and/or attached, iminegroups) and are not contained in uncoordinating hydrocarbons/rings mayor may Component Heterocyclic Rings (N—N not have halogen or polarizingor water- Bidentates, N—N Tridentates, N—N insolubilizing/solubilizinggroups attached. Tetradentates, and N—N Hexadentates) N ValenceStabilizer #14: Macrocyclic ligands containing a total of four, Four-,Six-, Eight-, or Ten-Membered six, eight, or ten Five-memberedheterocyclic Macrocyclics, Macrobicyclics, and rings containing nitrogenbinding sites. Can Macropolycyclics (including Catapinands, includeother hydrocarbon/ring systems bound Cryptands, Cyclidenes, andSepulchrates) to this macrocyclic ligand, but they do not wherein allBinding Sites are composed of coordinate with the stabilized, highvalence Nitrogen and are contained in Component metal ion. This ligandand/or attached, 5-Membered Heterocyclic Rings (N—N uncoordinatinghydrocarbon/rings may or may Bidentates, N—N Tridentates, N—N not havehalogen or polarizing or water- Tetradentates, or N—N Hexadentates)insolubilizing groups attached. N Valence Stabilizer #15: Macrocyclicligands containing at least one 5- Four-, Six-, Eight-, or Ten-Memberedmembered heterocyclic ring. These Macrocyclics, Macrobicyclics, andheterocyclic rings provide nitrogen binding sites Macropolycyclics(including Catapinands, to valence stabilize the central metal ion.Other Cryptands, Cyclidenes, and Sepulchrates) amine or imine bindingsites can also be wherein all Binding Sites are composed of included inthe macrocyclic ligand, so long as Nitrogen and are contained in a thetotal number of binding sites is four, six, Combination of 5-MemberedHeterocyclic eight, or ten. Can include other Rings and Amine or ImineGroups (N—N hydrocarbon/ring systems bound to this Bidentates, N—NTridentates, N—N macrocyclic ligand, but they do not coordinateTetradentates, or N—N Hexadentates) with the stabilized, high valencemetal ion. This ligand and/or attached, uncoordinating hydrocarbon/ringsmay or may not have halogen or polarizing or water-insolubilizing groupsattached. N Valence Stabilizer #16: Macrocyclic ligands containing atotal of four, Four-, Six-, Eight-, or Ten-Membered six, eight, or tensix-membered heterocyclic Macrocyclics, Macrobicyclics, and ringscontaining nitrogen binding sites. Can Macropolycyclics (includingCatapinands, include other hydrocarbon/ring systems bound Cryptands,Cyclidenes, and Sepulchrates) to this macrocyclic ligand, but they donot wherein all Binding Sites are composed of coordinate with thestabilized, high valence Nitrogen and are contained in Component metalion. This ligand and/or attached, 6-Membered Heterocyclic Rings (N—Nuncoordinating hydrocarbon/rings may or may Bidentates, N—N Tridentates,N—N not have halogen or polarizing or water- Tetradentates, or N—NHexadentates) insolubilizing groups attached. N Valence Stabilizer #17:Macrocyclic ligands containing at least one 6- Four-, Six-, Eight-, orTen-Membered membered heterocyclic ring. These Macrocyclics,Macrobicyclics, and heterocyclic rings provide nitrogen binding sitesMacropolycyclics (including Catapinands, to valence stabilize thecentral metal ion. Other Cryptands, Cyclidenes, and Sepulchrates) amineor imine binding sites can also be wherein all Binding Sites arecomposed of included in the macrocyclic ligand, so long as Nitrogen andare contained in a the total number of binding sites is four, six,Combination of 6-Membered Heterocyclic eight, or ten. Can include otherRings and Amine or Imine Groups (N—N hydrocarbon/ring systems bound tothis Bidentates, N—N Tridentates, N—N macrocyclic ligand, but they donot coordinate Tetradentates, or N—N Hexadentates) with the stabilized,high valence metal ion. This ligand and/or attached, uncoordinatinghydrocarbon/rings may or may not have halogen or polarizing orwater-insolubilizing groups attached. N Valence Stabilizer #18:R′—NH—C(—R)═N—R′′, where R, R′, and R′′ Amidines and Diamidines (N—NBidentates represent H or any organic functional group and N—NTetradentates) wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #19:RR′—N—C(═NH)—NR′′—C(═NH)—NR′′′R′′′′ for Biguanides (ImidodicarbonimidicDiamides biguanides, RR′—N—C(═NH)—NR′′—NH—C(═NH)— or Dihydrazides),Biguanidines, NR′′′R′′′′ for biguanidines, where R, R′, R′′,Imidotricarbonimidic Diamides or R′′′, and R′′′′ represent H, NH₂, orany organic Dihydrazides, Imidotetracarbonimidic functional groupwherein the number of carbon Diamides or Dihydrazides, Dibiguanides,atoms ranges from 0 to 40, halogen or Bis(biguanidines), Polybiguanides,and polarizing or water-insolubilizing/solubilizing Poly(biguanidines)(N—N Bidentates, N—N groups attached. Ligand can also containTridentates, N—N Tetradentates, and N—N nonbinding N, O, S, or P atoms.Hexadentates) N Valence Stabilizer #20:RR′—N—C(═NH)—CR′′R′′′—C(═NH)—NR′′′′R′′′′′, Diamidinomethanes, where R,R′, R′′, R′′′, R′′′′, and R′′′′′ represent Bis(amidinomethanes), and H,NH₂, or any organic functional group Poly(amidinomethanes) (N—NBidentates, wherein the number of carbon atoms ranges N—N Tridentates,N—N Tetradentates, from 0 to 40, optionally having halogen or and N—NHexadentates) polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #21: RR′—N—C(═NH)—NR′′—C(═NH)—R′′′ forImidoylguanidines, Amidinoguanidines, imidoylguanidines, andRR′—N—C(═NH)—NR′′— Bis(imidoylguanidines), NH—C(═NH)—R′′′ foramidinoguanidines, where Bis(amidinoguanidines), R, R′, R′′, and R′′′represent H, NH₂, or any Poly(imidoylguanidines), and organic functionalgroup wherein the number of Poly(amidinoguanidines) (N—N Bidentates,carbon atoms ranges from 0 to 40, optionally N—N Tridentates, N—NTetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #22:RR′—N—C(═NH)—O—C(═NH)—NR′′R′′′, where R, Diformamidine oxides(Dicarbonimidic R′, R′′, and R′′′ represent H, NH₂, or any Diamides orDihydrazides), organic functional group wherein the number ofTricarbonimidic Diamides or Dihydrazides, carbon atoms ranges from 0 to40, optionally Tetracarbonimidic Diamides or having halogen orpolarizing or water- Dihydrazides, Bis(diformamidine oxides),insolubilizing/solubilizing groups attached. and Poly(diformamidineoxides) (N—N Ligand can also contain nonbinding N, O, S, or Bidentates,N—N Tridentates, N—N P atoms. Tetradentates) N Valence Stabilizer #23:RR′—N—C(═NH)—S—C(═NH)—NR′′R′′′, where R, Diformamidine Sulfides R′, R′′,and R′′′ represent H, NH₂, or any (Thiodicarbonimidic Diamides ororganic functional group wherein the number of Dihydrazides),Thiotricarbonimidic carbon atoms ranges from 0 to 40, optionallyDiamides or Dihydrazides, having halogen or polarizing or water-Thiotetracarbonimidic Diamides or insolubilizing/solubilizing groupsattached. Dihydrazides, Bis(diformamidine sulfides), Ligand can alsocontain nonbinding N, O, S, or and Poly(diformamidine sulfides) (N—N Patoms. Bidentates, N—N Tridentates, N—N Tetradentates) N ValenceStabilizer #24: R—O—C(═NH)—NR′—C(═NH)—O—R′′ for ImidodicarbonimidicAcids, imidodicarbomimidic acids, and R—O—C(═NH)— DiimidodicarbonimidicAcids, NR′—NH—C(═NH)—O—R′′ for Imidotricarbonimidic Acids,diimidodicarbonimidic acids, where R, R′, and ImidotetracarbonimidicAcids, and R′′ represent H, NH₂, or any organic functional derivativesthereof (N—N Bidentates, N—N group wherein the number of carbon atomsTridentates, N—N Tetradentates, and N—N ranges from 0 to 40, optionallyhaving halogen Hexadentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #25:R—S—C(═NH)—NR′—C(═NH)—S—R′′ for Thioimidodicarbonimidic Acids,thioimidodicarbonimidic acids, and R—S— Thiodiimidodicarbonimidic Acids,C(═NH)—NR′—NH—C(═NH)—S—R′′ for Thioimidotricarbonimidic Acids,thiodiimidodicarbonimidic acids, where R, R′, ThioimidotetracarbonimidicAcids, and and R′′ represent H, NH₂, or any organic derivatives thereof(N—N Bidentates, N—N functional group wherein the number of carbonTridentates, N—N Tetradentates, and N—N atoms ranges from 0 to 40,optionally having Hexadentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #26:R—C(═NH)—NR′—C(═NH)—R′′ for Diimidoylimines, Diimidoylhydrazides,diimidoylimines, and R—C(═NH)—NR′—NH— Bis(diimidoylimines), C(═NH)—R′′for diimidoylhydrazides, where R, Bis(diimidoylhydrazides), R′, and R′′represent H, NH₂, or any organic Poly(diimidoylimines), and functionalgroup wherein the number of carbon Poly(diimidoylhydrazides) (N—N atomsranges from 0 to 40, optionally having Tridentates and N—N Hexadentates)halogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #27: RR′—N—S(═NH)(═O)—OR′′ or RR′—N— Imidosulfamides,Diimidosulfamides, S(═NH)(═O)—N—R′′R′′′ for imidosulfamides, andBis(imidosulfamides), RR′—N—S(═NH)(═NH)—OR′′ or RR′—N—Bis(diimidosulfamides), S(═NH)(═NH)—N—R′′R′′′ for diimidosulfamides,Poly(imidosulfamides), and where R, R′, R′′, and R′′′ represent H, NH₂,or Poly(diimidosulfamides) (N—N Bidentates, any organic functional groupwherein the N—N Tridentates, N—N Tetradentates, number of carbon atomsranges from 0 to 40, and N—N Hexadentates) optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N Valence Stabilizer#28: (NH═)P(—NRR′)(—NR′′R′′′)(—NR′′′′R′′′′′), where PhosphoramidimidicTriamides, R, R′, R′′, R′′′, R′′′′, and R′′′′′ represent H, NH₂,Bis(phosphoramidimidic triamides), and or any organic functional groupwherein the Poly(phosphoramidimidic triamides) and number of carbonatoms ranges from 0 to 40, derivatives thereof (N—N Bidentates, N—Noptionally having halogen or polarizing or Tridentates, N—NTetradentates, and N—N water-insolubilizing/solubilizing groupsHexadentates) attached. Ligand can also contain nonbinding N, O, S, or Patoms. N Valence Stabilizer #29: (NH═)P(—NRR′)(OH)₂ forphosphoramidimidic Phosphoramidimidic Acid, acid, and(NH═)P(—NRR′)(—NR′′R′′′)(OH) for Phosphorodiamidimidic Acid,phosphorodiamidimidic acid, where R, R′, R′′, Bis(PhosphoramidimidicAcid), and R′′′ represent H, NH₂, or any organicBis(Phosphorodiamidimidic Acid), functional group wherein the number ofcarbon Poly(Phosphoramidimidic Acid), atoms ranges from 0 to 40,optionally having Poly(Phosphorodiamidimidic Acid), and halogen orpolarizing or water- derivatives thereof (N—N Bidentates, N—Ninsolubilizing/solubilizing groups attached. Tridentates, N—NTetradentates, and N—N Ligand can also contain nonbinding N, O, S, orHexadentates) P atoms. N Valence Stabilizer #30: (NH═)P(—NRR′)(SH)₂ forPhosphoramidimidodithioic Acid, phosphoramidimidodithioic acid, and(NH═)P(— Phosphorodiamidimidothioic Acid, NRR′)(—NR′′R′′′)(SH) forBis(Phosphoramidimidodithioic Acid), phosphorodiamidimidothioic acid,where R, R′, Bis(Phosphorodiamidimidothioic Acid), R′′, and R′′′represent H, NH₂, or any organic Poly(Phosphoramidimidodithioic Acid),functional group wherein the number of carbonPoly(Phosphorodiamidimidothioic Acid), atoms ranges from 0 to 40,optionally having and derivatives thereof (N—N Bidentates, N—N halogenor polarizing or water- Tridentates, N—N Tetradentates, and N—Ninsolubilizing/solubilizing groups attached. Hexadentates) Ligand canalso contain nonbinding N, O, S, or P atoms. N Valence Stabilizer #31:R—N═N—R′ for azo compounds, R—N═N—NH—R′ Azo compounds includingtriazenes with for triazenes, where R, and R′ represent H or amino,imino, oximo, diazeno, or hydrazido any organic functional group whereinthe substitution at the ortho- (for aryl) or alpha- number of carbonatoms ranges from 0 to 40, or beta- (for alkyl) positions, Bis[o-(H₂N—)optionally having halogen or polarizing or or alpha- or beta-(H₂N—)azocompounds], or water-insolubilizing/solubilizing groups Poly[o-(H₂N—) oralpha- or beta-(H₂N—)azo attached. (Must include ortho-amino, imino,compounds) (N—N Bidentates, N—N oximo, diazeno, or hydrazido substitutedaryl Tridentates, N—N Tetradentates, or N—N azo compounds, and alpha- orbeta-amino, Hexadentates) imino, oximo, diazeno, or hydrazido alkyl azocompounds.) Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #32: R—N═N—C(═NH)—NR′R′′ for Diazeneformimidamidesdiazeneformimidamides, and R—N═N—CR′R′′— (Diazeneamidines),Diazeneacetimidamides C(═NH)—NR′′′R′′′′ for diazeneacetimidamides,(Diazene-alpha-amidinoalkanes(alkenes)), where R, R′, R′′, R′′′, andR′′′′ represent H, Bis(diazeneformimidamides), NH₂, or any organicfunctional group wherein Bis(diazeneacetimidamides), the number ofcarbon atoms ranges from 0 to Poly(diazeneformimidamides), and 40,optionally having halogen or polarizing or Poly(diazeneacetimidamides)(N—N water-insolubilizing/solubilizing groups Bidentates, N—NTetradentates, and N—N attached. Ligand can also contain nonbinding N,Hexadentates) O, S, or P atoms. N Valence Stabilizer #33:R—N═N—C(═NH)—OR′ for diazeneformimidic Diazeneformimidic Acid, acid, andR—N═N—CR′R′′—C(═NH)—OR′′′ for Diazeneacetimidic Acid, diazeneacetimidicacid, where R, R′, R′′, and Bis(diazeneformimidic acid), R′′′ representH, NH₂, or any organic functional Bis(diazeneacetimidic acid), groupwherein the number of carbon atoms Poly(diazeneformimidic acid), rangesfrom 0 to 40, optionally having halogen Poly(diazeneacetimidic acid),and or polarizing or water- derivatives thereof (N—N Bidentates, N—Ninsolubilizing/solubilizing groups attached. Tetradentates, and N—NHexadentates) Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #34: R—N═N—C(═NH)—SR′ for DiazeneformimidothioicAcid, diazeneformimidothioic acid, and R—N═N— DiazeneacetimidothioicAcid, CR′R′′—C(═NH)—SR′′′ for Bis(diazeneformimidothioic acid),diazeneacetimidothioic acid, where R, R′, R′′,Bis(diazeneacetimidothioic acid), and R′′′ represent H, NH₂, or anyorganic Poly(diazeneformimidothioic acid), functional group wherein thenumber of carbon Poly(diazeneacetimidothioic acid), and atoms rangesfrom 0 to 40, optionally having derivatives thereof (N—N Bidentates, N—Nhalogen or polarizing or water- Tetradentates, and N—N Hexadentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #35:R—N═N—C(═NH)—R′ or R—N═N—CR′R′′— Imidoyldiazenes, Bis(imidoyldiazenes),and C(═NH)—R′′′, where R, R′, R′′, and R′′′ Poly(imidoyldiazenes), (N—NBidentates, N—N represent H, NH₂, or any organic functionalTetradentates and N—N Hexadentates) group wherein the number of carbonatoms ranges from 0 to 40, optionally having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #36:RR′—N—C(═NH)—N═N—C(═NH)—NR′′R′′′ for Diazenediformimidamides (1,2-diazenediformimidamides, and RR′—N—C(═NH)— Diazenediamidines),CR′′R′′′—N═N—CR′′′′R′′′′′—C(═NH)—NR′′′′′′R′′′′′′′Diazenediacetimidamides (1,2-Diazene-di- for diazenediacetimidamides,where R, R′, R′′, alpha-amidinoalkanes(alkenes)), R′′′, R′′′′, R′′′′′,R′′′′′′, and R′′′′′′′ represent H, Bis(diazenediformimidamides), NH₂, orany organic functional group wherein Bis(diazenediacetimidamides), thenumber of carbon atoms ranges from 0 to Poly(diazenediformimidamides),and 40, optionally having halogen or polarizing orPoly(diazenediacetimidamides) (N—N water-insolubilizing/solubilizinggroups Tridentates and N—N Hexadentates) attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #37:RO—C(═NH)—N═N—C(═NH)—OR′ for Diazenediformimidic Acid,diazenediformimidic acid, and RO—C(═NH)— Diazenediacetimidic Acid,CR′R′′—N═N—CR′′′R′′′′—C(═NH)—OR′′′′′ for Bis(diazenediformimidic acid),diazenediacetimidic acid, where R, R′, R′′, R′′′,Bis(diazenediacetimidic acid), R′′′′, and R′′′′′ represent H, NH₂, orany organic Poly(diazenediformimidic acid), and functional group whereinthe number of carbon Poly(diazenediacetimidic acid), and atoms rangesfrom 0 to 40, optionally having derivatives thereof (N—N Tridentates andN—N halogen or polarizing or water- Hexadentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #38:RS—C(═NH)—N═N—C(═NH)—SR′ for Diazenediformimidothioic Acid,diazenediformimidothioic acid, and RS— Diazenediacetimidothioic Acid,C(═NH)—CR′R′′—N═N—CR′′′R′′′′—C(═NH)—SR′′′′′ Bis(diazenediformimidothioicacid), for diazenediacetimidothioic acid, where R, R′,Bis(diazenediacetimidothioic acid), R′′, R′′′, R′′′′, and R′′′′′represent H, NH₂, or any Poly(diazenediformimidothioic acid), andorganic functional group wherein the number ofPoly(diazenediacetimidothioic acid), and carbon atoms ranges from 0 to40, optionally derivatives thereof (N—N Tridentates and N—N havinghalogen or polarizing or water- Hexadentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #39:R—C(═NH)—N═N—C(═NH)—R′′ or R—C(═NH)— Diimidoyldiazenes,Bis(diimidoyldiazenes), CR′R′′—N═N—CR′′′R′′′′—C(═NH)—R′′′′′, where R,and Poly(diimidoyldiazenes), (N—N R′, R′′, R′′′, R′′′′, and R′′′′′represent H, NH₂, or Tridentates and N—N Hexadentates) any organicfunctional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #40:R—N═N—CR′═N—NR′′R′′′, where R, R′, R′′, and Ortho-amino (or -hydrazido)Substituted R′′′ represent H, or any organic functional Formazans,Bis(o-amino or -hydrazido group wherein the number of carbon atomssubstituted formazans), and Poly(o-amino ranges from 0 to 40, optionallyhaving halogen or -hydrazido substituted formazans) (N—N or polarizingor water- Bidentates, N—N Tridentates, N—N insolubilizing/solubilizinggroups attached. Tetradentates, and N—N Hexadentates) (Must includeortho-amine or hydrazide substituted aryl R derivatives, and beta-amineor hydrazide substituted alkyl R derivatives.) Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #41:RR′C═N—N═CR′′R′′′ or RR′C═N—NR′′R′′′ (for Ortho-amino (or -hydrazido)Substituted ketazines), where R, R′, R′′, and R′′′ represent Azines(including ketazines), Bis(o-amino H, or any organic functional groupwherein the or hydrazido substituted azines), and number of carbon atomsranges from 0 to 40, Poly(o-amino or hydrazido substituted optionallyhaving halogen or polarizing or azines) (N—N Bidentates, N—NTridentates, water-insolubilizing/solubilizing groups N—N Tetradentates,and N—N Hexadentates) attached. (Must include ortho-amine or hydrazidesubstituted aryl R derivatives, and beta-amine or hydrazide substitutedalkyl R derivatives.) Ligand can also contain nonbinding N, O, S, or Patoms. N Valence Stabilizer #42: RR′C═N—R′′, where R, R′, and R′′represent H, Schiff Bases with one Imine (C═N) Group or any organicfunctional group wherein the and with ortho- or alpha- or beta-amino ornumber of carbon atoms ranges from 0 to 40, imino or oximo or diazeno orhydrazido optionally having halogen or polarizing or substitution (N—NBidentates, N—N water-insolubilizing/solubilizing groups Tridentates,N—N Tetradentates, N—N attached. (Must contain ortho- or alpha- or beta-Pentadentates, or N—N Hexadentates). Also amino or imino or oximo ordiazeno or includes hydrazones with ortho-N hydrazido substitution.)Ligand can also substitution. contain nonbinding N, O, S, or P atoms. NValence Stabilizer #43: RR′C═N—R′′—N═CR′′′R′′′′ or R—N═C—R′—C═N— SchiffBases with two Imine (C═N) Groups R′ or RC═N—R′—N═CR′′, where R, R′,R′′, R′′′, and without ortho- (for aryl constituents) or and R′′′′represent H, or any organic functional alpha- or beta- (for alkylconstituents) group wherein the number of carbon atoms hydroxy, carboxy,carbonyl, thiol, ranges from 0 to 40, optionally having halogenmercapto, thiocarbonyl, amino, imino, or polarizing or water- oximo,diazeno, or hydrazido substitution insolubilizing/solubilizing groupsattached. (Not (N—N Bidentates). Also includes including ortho-, alpha-,or beta-hydroxy, dihydrazones. carboxy, carbonyl, thiol, mercapto,thiocarbonyl, amino, imino, oximo, diazeno, or hydrazido substitution.)Ligand can also contain nonbinding N, O, S, or P atoms. N ValenceStabilizer #44: RR′C═N—R′′—N═CR′′′R′′′′ or R—N═C—R′—C═N— Schiff Baseswith two Imine (C═N) Groups R′ or RC═N—R′—N═CR′′, where R, R′, R′′,R′′′, and with ortho- or alpha- or beta-amino or and R′′′′ represent H,or any organic functional imino or oximo or diazeno or hydrazido groupwherein the number of carbon atoms substitution (N—N Tridentates, N—Nranges from 0 to 40, optionally having halogen Tetradentates, N—NPentadentates, or N—N or polarizing or water- Hexadentates). Alsoincludes hydrazones insolubilizing/solubilizing groups attached. withortho-N substitution. (Must contain ortho- or alpha- or beta-amino orimino or oximo or diazeno or hydrazido substitution.) Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #45:N(—R—N═CR′R′′)₃, where R, R′, and R′′ Schiff Bases with three Imine(C═N) represent H, or any organic functional group Groups and withoutortho- (for aryl wherein the number of carbon atoms ranges constituents)or alpha- or beta- (for alkyl from 0 to 40, optionally having halogen orconstituents) hydroxy, carboxy, carbonyl, polarizing orwater-insolubilizing/solubilizing thiol, mercapto, thiocarbonyl, amino,imino, groups attached. (Not including ortho-, alpha-, oximo, diazeno,or hydrazido substitution or beta-hydroxy, carboxy, carbonyl, thiol,(N—N Tridentates). Also includes mercapto, thiocarbonyl, amino, imino,oximo, trihydrazones. diazeno, or hydrazido substitution.) Ligand canalso contain nonbinding N, O, S, or P atoms. N Valence Stabilizer #46:N(—R—N═CR′R′′)₃, where R, R′, and R′′ Schiff Bases with three Imine(C═N) represent H, or any organic functional group Groups and withortho- or alpha- or beta- wherein the number of carbon atoms rangesamino or imino or oximo or diazeno or from 0 to 40, optionally havinghalogen or hydrazido substitution (N—N Tetradentates, polarizing orwater-insolubilizing/solubilizing N—N Pentadentates, or N—NHexadentates) groups attached. (Must contain ortho- or alpha- orbeta-amino or imino or oximo or diazeno or hydrazido substitution.)Ligand can also contain nonbinding N, O, S, or P atoms. S ValenceStabilizer #1: Macrocyclic ligands containing two, four, or sixMacrocyclic, Macrobicyclic, and thioketone binding sites to valencestabilize the Macropolycyclic Oligothioketones central metal ion. Caninclude other (including Catapinands, Cryptands, hydrocarbon or ringsystems bound to this Cyclidenes, and Sepulchrates) wherein allmacrocyclic ligand, but they do not coordinate Binding Sites arecomposed of Thioketones with the stabilized, high valence metal ion.This (typically in the beta position) (S—S ligand and/or attached,uncoordinating Bidentates, S—S Tetradentates, and S—S hydrocarbons/ringsmay or may not have Hexadentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. S Valence Stabilizer #2:Macrocyclic ligands containing two, four, six, Macrocyclic,Macrobicyclic, and or eight 1,1-dithiolene binding sites to valenceMacropolycyclic Dithiolenes (including stabilize the central metal ion.Can include other Catapinands, Cryptands, Cyclidenes, and hydrocarbon orring systems bound to this Sepulchrates) wherein all Binding Sites aremacrocyclic ligand, but they do not coordinate composed of alpha, alphadithiols (meaning with the stabilized, high valence metal ion. This twothiol groups on a single carbon atom in ligand and/or attached,uncoordinating the ring) (S—S Bidentates, S—S hydrocarbons/rings may ormay not have Tetradentates, and S—S Hexadentates) halogen or polarizingor water- insolubilizing/solubilizing groups attached. S ValenceStabilizer #3: RC(═S)—NR′—C(═S)—R′′ for Dithioimidodialdehydes,dithioimidodialdehydes, and RC(═S)—NR′—NH— Dithiohydrazidodialdehydes(thioacyl C(═S)—R′′ for dithiohydrazidodialdehydes thiohydrazides),(thioacyl thiohydrazides), where R, R′, and R′′Bis(dithioimidodialdehydes), represent H, NH₂, or any organic functionalBis(dithiohydrazidodialdehydes), group wherein the number of carbonatoms Poly(dithioimidodialdehydes), and ranges from 0 to 40, optionallyhaving halogen Poly(dithiohydrazidodialdehydes) (S—S or polarizing orwater- Bidentates, S—S Tridentates, S—S insolubilizing/solubilizinggroups attached. Tetradentates) Ligand can also contain nonbinding N, O,S, or P atoms. S Valence Stabilizer #4: R—O—C(═S)—NR′—C(═S)—O—R′′ orR—S—C(═S)— Dithioimidodicarbonic acids, NR′—C(═S)—S—R′′ fordithioimidodicarbonic Dithiohydrazidodicarbonic acids, acids, andR—O—C(═S)—NR′—NH—C(═S)—O—R′′ or Bis(dithioimidodicarbonic acids),R—S—C(═S)—NR′—NH—C(═S)—S—R′′ for Bis(dithiohydrazidodicarbonic acids),dithiohydrazidodicarbonic acids, where R, R′, Poly(dithioimidodicarbonicacids), and R′′ represent H, NH₂, or any organicPoly(dithiohydrazidodicarbonic acids) and functional group wherein thenumber of carbon derivatives thereof (S—S Bidentates, S—S atoms rangesfrom 0 to 40, optionally having Tridentates, S—S Tetradentates) halogenor polarizing or water- insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. S ValenceStabilizer #5: R—C(═S)—CR′R′′—C(═S)—R′′′ where R, R′, R′′,1,3-Dithioketones (Dithio-beta-ketonates), and R′′′ represent H, NH₂, orany organic 1,3,5-Trithioketones, Bis(1,3- functional group wherein thenumber of carbon Dithioketones), and Poly(1,3- atoms ranges from 0 to40, optionally having Dithioketones) (S—S Bidentates, S—S halogen orpolarizing or water- Tridentates, S—S Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #6:R—C(═S)—C(═S)—R′ where R and R′ represent H, 1,2-Dithioketones(Dithiolenes, Dithio- NH₂, or any organic functional group whereinalpha-ketonates), 1,2,3-Trithioketones, the number of carbon atomsranges from 0 to Dithiotropolonates, ortho-Dithioquinones, 40,optionally having halogen or polarizing or Bis(1,2-Dithioketones), andPoly(1,2- water-insolubilizing/solubilizing groups Dithioketones) (S—SBidentates, S—S attached. Ligand can also contain nonbinding N,Tridentates, S—S Tetradentates) O, S, or P atoms. S Valence Stabilizer#7: RR′—N—C(═S)—CR′′R′′′—C(═S)—N—R′′′′R′′′′′ where Dithiomalonamides R,R′, R′′, R′′′, R′′′′, and R′′′′′ represent H, NH₂,(Dithiomalonodiamides), or any organic functional group wherein theBis(dithiomalonamides), and number of carbon atoms ranges from 0 to 40,Polydithiomalonamides (S—S Bidentates, S—S optionally having halogen orpolarizing or Tridentates, S—S Tetradentates)water-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #8:RR′—N—C(═S)—CR′′R′′′—C(═S)—R′′′′ where R, R′, 2-Thioacylthioacetamides,Bis(2- R′′, R′′′, and R′′′′ represent H, NH₂, or anythioacylthioacetamides), and Poly(2- organic functional group whereinthe number of thioacylthioacetamides) (S—S Bidentates, S—S carbon atomsranges from 0 to 40, optionally Tridentates, S—S Tetradentates) havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #9: R—C(═S)—S—C(═S)—R′ where R and R′ representDithioacyl sulfides, Bis(dithioacyl sulfides), H or any organicfunctional group wherein the and Poly(dithioacyl sulfides) (S—S numberof carbon atoms ranges from 0 to 40, Bidentates, S—S Tridentates, S—Soptionally having halogen or polarizing or Tetradentates)water-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #10:RR′—N—C(═S)—S—C(═S)—N—R′′R′′′ where R, R′, Trithiodicarbonic Diamides,R′′, and R′′′ represent H, NH₂ or any organic Bis(trithiodicarbonicdiamides), and functional group wherein the number of carbonPoly(trithiodicarbonic diamides) (S—S atoms ranges from 0 to 40,optionally having Bidentates, S—S Tridentates, S—S halogen or polarizingor water- Tetradentates) insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. S ValenceStabilizer #11: R—S—C(═S)—S—C(═S)—S—R′ for Pentathio-, Tetrathio-, orTrithiodicarbonic pentathiodicarbonic acids, R—O—C(═S)—S—C(═S)— Acids,Bis(pentathio-, tetrathio-, or S—R′ for tetrathiodicarbonic acids, andR—O— trithiodicarbonic acids), Poly(pentathio-, C(═S)—S—C(═S)—O—R′ forpentathiodicarbonic tetrathio-, or trithiodicarbonic acids), and acids,where R and R′ represent H, NH₂ or any derivatives thereof (S—SBidentates, S—S organic functional group wherein the number ofTridentates, S—S Tetradentates) carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #12:(R—O—)(R′—O—)P(═S)—P(═S)(—O—R′′)(—O—R′′′); (R— DithiohypophosphoricAcids, O—)(R′—S—)P(═S)—P(═S)(—S—R′′)(—O—R′′′); or (R—Bis(dithiohypophosphoric acids), andS—)(R′—S—)P(═S)—P(═S)(—S—R′′)(—S—R′′′), where Poly(dithiohypophosphoricacids), and R, R′, R′′, and R′′′ represent H, NH₂ or any derivativesthereof (S—S Bidentates, S—S organic functional group wherein the numberof Tridentates, S—S Tetradentates) carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. Note: these ligands are not to beconfused with hypophosphorous acid derivatives (hypophosphites) (R—O—)R′′R′′′P(═O) which are very reducing and therefore unacceptable forstabilization of high valence states in metal ions. S Valence Stabilizer#13: (RR′—N—)(R′′R′′′—N—)P(═S)—P(═S)(—N— Dithiohypophosphoramides,R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′), where R, R′, R′′, R′′′,Bis(dithiohypophosphoramides), and R′′′′, R′′′′′, R′′′′′′, and R′′′′′′′represent H, NH₂ or Poly(dithiohypophosphoramides) (S—S any organicfunctional group wherein the Bidentates, S—S Tridentates, S—S number ofcarbon atoms ranges from 0 to 40, Tetradentates) optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. Note:these ligands are not to be confused with hypophosphorous acidderivatives (hypophosphites) (R—O—) R′′R′′′P(═O) which are very reducingand therefore unacceptable for stabilization of high valence states inmetal ions. S Valence Stabilizer #14:(R—O—)(R′—O—)P(═S)—NH—P(═S)(—O—R′′)(—O— Dithioimidodiphosphoric Acids,R′′′); (R—O—)(R′—S—)P(═S)—NH—P(═S)(—S—R′′)(—O—Dithiohydrazidodiphosphoric Acids, R′′′); or(R—S—)(R′—S—)P(═S)—NH—P(═S)(—S—R′′)(— Bis(dithioimidodiphosphoricAcids), S—R′′′) for dithioimidodiphosphoric acids, and —Bis(dithiohydrazidodiphosphoric Acids), NH—NH— derivatives forPoly(dithioimidodiphosphoric Acids), dithiohydrazidodiphosphoric acids,where R, Poly(dithiohydrazidodiphosphoric Acids), R′, R′′, and R′′′represent H, NH₂ or any organic and derivatives thereof (S—S Bidentates,S—S functional group wherein the number of carbon Tridentates, S—STetradentates) atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#15: (RR′—N—)(R′′R′′′—N—)P(═S)—NH—P(═S)(—N— Dithioimidodiphosphoramides,R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′) for Dithiohydrazidodiphosphoramides,dithioimidophosphoramides, and (RR′—N—)Bis(dithioimidodiphosphoramides), (R′′R′′′—N—)P(═S)—NH—NH—P(═S)(—N—Bis(dithiohydrazidodiphosphoramides), R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′)for Poly(dithioimidodiphosphoramides), anddithiohydrazidodiphosphoramides, where R, R′,Poly(dithiohydrazidodiphosphoramides) (S—S R′′, R′′′, R′′′′, R′′′′′,R′′′′′′, and R′′′′′′′ represent Bidentates, S—S Tridentates, S—S H, NH₂or any organic functional group wherein Tetradentates) the number ofcarbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#16: (RR′—N—)(R′′R′′′—N—)P(═S)—S—P(═S)(—N— Dithiodiphosphoramides,R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′), or (RR′—N—)(R′′R′′′—Bis(dithioiphosphoramides), and N—)P(═S)—O—P(═S)(—N—R′′′′R′′′′′)(—N—Poly(dithiodiphosphoramides) (S—S R′′′′′′R′′′′′′′), where R, R′, R′′,R′′′, R′′′′, R′′′′′, Bidentates, S—S Tridentates, S—S R′′′′′′, andR′′′′′′′ represent H, NH₂ or any Tetradentates) organic functional groupwherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S Valence Stabilizer #17: (R—O—)(R′—O—)P(═S)—O—P(═S)(—O—R′′)(—O—R′′′);Dithiodiphosphoric Acids, (R—O—)(R′—O—)P(═S)—S—P(═S)(—O—R′′)(—O—R′′′);Bis(dithioiphosphoric Acids),(R—O—)(R′—S—)P(═S)—O—P(═S)(—S—R′′)(—O—R′′′); Poly(dithiodiphosphoricAcids), and (R—O—)(R′—S—)P(═S)—S—P(═S)(—S—R′′)(—O—R′′′); or derivativesthereof (S—S Bidentates, S—S(R—S—)(R′—S—)P(═S)—S—P(═S)(—S—R′′)(—S—R′′′), Tridentates, S—STetradentates) where R, R′, R′′, R′′′, R′′′′, R′′′′′, R′′′′′′, andR′′′′′′′ represent H, NH₂ or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#18: (O═)P(—S—R)(—S—R′)(—S—R′′) or (S═)P(—S—R)(—S— TrithiophosphoricAcids R′)(—O—R′′), where R, R′, and R′′ represent H, (PhosphorotrithioicAcids), NH₂ or any organic functional group whereinBis(trithiophosphoric acids), the number of carbon atoms ranges from 0to Poly(trithiophosphoric acids), and 40, optionally having halogen orpolarizing or derivatives thereof (S—S Bidentates, S—Swater-insolubilizing/solubilizing groups Tridentates, S—S Tetradentates)attached. Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #19: (O═)P(—S—R)(—S—R′)(—O—R′′) or (S═)P(—S—R)(—O—Dithiophosphoric Acids (Phosphorodithioic R′)(—O—R′′), where R, R′, andR′′ represent H, Acids), Bis(dithiophosphoric acids), NH₂ or any organicfunctional group wherein Poly(dithiophosphoric acids), and the number ofcarbon atoms ranges from 0 to derivatives thereof (S—S Bidentates, S—S40, optionally having halogen or polarizing or Tridentates, S—STetradentates) water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#20: (S═)P(—S—R)(—S—R′)(—S—R′′), where R, R′, and R′′Tetrathiophosphoric Acids represent H, NH₂ or any organic functional(Phosphorotetrathioic Acids), group wherein the number of carbon atomsBis(tetrathiophosphoric acids), ranges from 0 to 40, optionally havinghalogen Poly(tetrathiophosphoric acids), and or polarizing or water-derivatives thereof (S—S Bidentates, S—S insolubilizing/solubilizinggroups attached. Tridentates, S—S Tetradentates) Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #21:(O═)P(—S—S—R)(—S—R′)(—S—R′′) or (S═)P(—S—S—Phosphoro(dithioperoxo)dithioic Acids, R)(—S—R′)(—O—R′′), where R, R′,and R′′ Bis[phosphoro(dithioperoxo)dithioic represent H, NH₂ or anyorganic functional Acids], group wherein the number of carbon atomsPoly[phosphoro(dithioperoxo)dithioic ranges from 0 to 40, optionallyhaving halogen Acids], and derivatives thereof (S—S or polarizing orwater- Bidentates, S—S Tridentates, S—S insolubilizing/solubilizinggroups attached. Tetradentates) Ligand can also contain nonbinding N, O,S, or P atoms. S Valence Stabilizer #22: (O═)P(—S—S—R)(—S—R′)(—O—R′′) or(S═)P(—S—S— Phosphoro(dithioperoxo)thioic Acids, R)(—O—R′)(—O—R′′),where R, R′, and R′′ Bis[phosphoro(dithioperoxo)thioic Acids], representH, NH₂ or any organic functional Poly[phosphoro(dithioperoxo)thioicAcids], group wherein the number of carbon atoms and derivatives thereof(S—S Bidentates, S—S ranges from 0 to 40, optionally having halogenTridentates, S—S Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #23:(S═)P(—S—S—R)(—S—R′)(—S—R′′), where R, R′, andPhosphoro(dithioperoxo)trithioic Acids, R′′ represent H, NH₂ or anyorganic functional Bis[phosphoro(dithioperoxo)trithioic group whereinthe number of carbon atoms Acids], ranges from 0 to 40, optionallyhaving halogen Poly[phosphoro(dithioperoxo)trithioic or polarizing orwater- Acids], and derivatives thereof (S—S insolubilizing/solubilizinggroups attached. Bidentates, S—S Tridentates, S—S Ligand can alsocontain nonbinding N, O, S, or Tetradentates) P atoms. S ValenceStabilizer #24: R—CR′(—SH)—CH₂—C(═S)—R′′, where R, R′, andBeta-Mercaptothioketones, Beta- R′′ represent H, NH₂ or any organicfunctional Mercaptothioaldehydes, Bis(beta- group wherein the number ofcarbon atoms mercaptothioketones), Bis(beta- ranges from 0 to 40,optionally having halogen mercaptothioaldehydes), Poly(beta- orpolarizing or water- mercaptothioketones), and Poly(beta-insolubilizing/solubilizing groups attached. mercaptothioaldehydes) (S—SBidentates, S—S Ligand can also contain nonbinding N, O, S, orTridentates, S—S Tetradentates) P atoms. S Valence Stabilizer #25:RR′—N—CH(—SH)—NR′′—C(═S)—NR′′′R′′′′, where N-(Aminomethylthiol)thioureas[N- R, R′, R′′, R′′′, and R′′′′ represent H, NH₂ or any(Aminomercaptomethyl)thioureas], Bis[N- organic functional group whereinthe number of (aminomethylthiol)thioureas], and Poly[N- carbon atomsranges from 0 to 40, optionally (aminomethylthiol)thioureas] (S—S havinghalogen or polarizing or water- Bidentates, S—S Tridentates, S—Sinsolubilizing/solubilizing groups attached. Tetradentates) Ligand canalso contain nonbinding N, O, S, or P atoms. S Valence Stabilizer #26:RR′—N—C(═S)—C(═S)—N—R′′R′′′, where R, R′, Dithiooxamides,Bis(dithiooxamides), and R′′, and R′′′ represent H, NH₂ or any organicPoly(dithiooxamides) (S—S Bidentates, S—S functional group wherein thenumber of carbon Tridentates, S—S Tetradentates) atoms ranges from 0 to40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #27:RR′—C═C(—S⁻)(—S⁻), where R and R′ represent H, 1,1-Dithiolates,Bis(1,1-dithiolates), and NH₂ or any organic functional group whereinPoly(1,1-dithiolates) (S—S Bidentates and S—S the number of carbon atomsranges from 0 to Tetradentates) 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#28: R—C(═S)(—S—R′) for dithiomonocarboxylic acids, DithiomonocarboxylicAcids, Tri- and and (R—S—)(S═)C—R′—C(═S)(—S—R′′) for tri- andTetrathiodicarboxylic Acids, tetrathiodicarboxylic acids, where R, R′,and R′′ Bis(dithiomonocarboxylic Acids), Bis(tri- represent H, NH₂ orany organic functional and tetrathiodicarboxylic acids), group whereinthe number of carbon atoms Poly(dithiomonocarboxylic acids), Poly(tri-ranges from 0 to 40, optionally having halogen and tetrathiodicarboxylicacids), and or polarizing or water- derivatives thereof (S—S Bidentatesand S—S insolubilizing/solubilizing groups attached. Tetradentates)Ligand can also contain nonbinding N, O, S, or P atoms. S ValenceStabilizer #29: R—C(═S)(—S—S—R′) for perthiomonocarboxylicPerthiomonocarboxylic Acids, acids, and (R—S—S—)(S═)C—R′—C(═S)(—S—S—R′′)Perthiodicarboxylic Acids, for perthiodicarboxylic acids, where R, R′,and Bis(perthiomonocarboxylic acids), R′′ represent H, NH₂ or anyorganic functional Bis(perthiodicarboxylic acids), group wherein thenumber of carbon atoms Poly(perthiomonocarboxylic acids), ranges from 0to 40, optionally having halogen Poly(perthiodicarboxylic acids), and orpolarizing or water- derivatives thereof (S—S Bidentates and S—Sinsolubilizing/solubilizing groups attached. Tetradentates) Ligand canalso contain nonbinding N, O, S, or P atoms. S Valence Stabilizer #30:R—S—C(═S)—O—R′ or R—S—C(═O)—S—R′ for Dithiocarbonates,Trithiocarbonates, dithiocarbonates, R—S—C(═S)—S—R′ forPerthiocarbonates, Bis(dithiocarbonates), trithiocarbonates, andR—S—S—C(═S)—S—R′ for Bis(trithiocarbonates), and perthiocarbonates,where R, and R′ represent H, Bis(perthiocarbonates) (S—S Bidentates andNH₂ or any organic functional group wherein S—S Tetradentates) thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#31: RR′N⁺═C(SH)(SH), where R and R′ represent Dithiocarbamates,Bis(dithiocarbamates), H, OH, SH, OR′′ (R′′ = C₁-C₃₀ alkyl or aryl), andPoly(dithiocarbamates) (including N- SR′′ (R′′ = C₁-C₃₀ alkyl or aryl),NH₂ or any hydroxydithiocarbamates and N- organic functional groupwherein the number of mercaptodithiocarbamates) (S—S Bidentates, carbonatoms ranges from 0 to 40, optionally S—S Tridentates, and S—STetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #32:RR′N—NR′′—C(═S)(SH), where R and R′ Dithiocarbazates (Dithiocarbazides),represent H, NH₂ or any organic functional Bis(dithiocarbazates), andgroup wherein the number of carbon atoms Poly(dithiocarbazates) (S—SBidentates, S—S ranges from 0 to 40, optionally having halogenTridentates, and S—S Tetradentates; or or polarizing or water- possiblyN—S Bidentates, N—S Tridentates, insolubilizing/solubilizing groupsattached. and N—S Tetradentates) Ligand can also contain nonbinding N,O, S, or P atoms. S Valence Stabilizer #33: Thiocyanates bound directlyto the high valence Thiocyanate ligands (S Monodentates) metal ion. OValence Stabilizer #1: RR′—N—C(═O)—NR′′—C(═O)—NR′′′R′′′′ for Biurets(Imidodicarbonic Diamides), biurets, and RR′—N—C(═O)—NR′′—NH—C(═O)—Isobiurets, Biureas, Triurets, Triureas, NR′′′R′′′′ for biureas, whereR, R′, R′′, R′′′, and Bis(biurets), Bis(isobiurets), Bis(biureas), R′′′′represent H, NH₂, or any organic functional Poly(biurets),Poly(isobiurets), and group wherein the number of carbon atomsPoly(biureas) (O—O Bidentates, O—O ranges from 0 to 40, optionallyhaving halogen Tridentates, O—O Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #2:RR′—N—C(═O)—NR′′—C(═O)—R′′′ where R, R′, Acylureas, Aroylureas,Bis(acylureas), R′′, and R′′′ represent H, NH₂, or any organicBis(aroylureas), Poly(acylureas), and functional group wherein thenumber of carbon Poly(aroylureas) (O—O Bidentates, O—O atoms ranges from0 to 40, optionally having Tridentates, O—O Tetradentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#3: RC(═O)—NR′—C(═O)—R′′ for imidodialdehydes, Imidodialdehydes,Hydrazidodialdehydes and RC(═O)—NR′—NH—C(═O)—R′′ for (Acyl hydrazides),Bis(imidodialdehydes), hydrazidodialdehydes (acyl hydrazides), whereBis(hydrazidodialdehydes), R, R′, and R′′ represent H, NH₂, or anyorganic Poly(imidodialdehydes), and functional group wherein the numberof carbon Poly(hydrazidodialdehydes) (O—O atoms ranges from 0 to 40,optionally having Bidentates, O—O Tridentates, O—O halogen or polarizingor water- Tetradentates) insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. O ValenceStabilizer #4: R—O—C(═O)—NR′—C(═O)—O—R′′ for Imidodicarbonic acids,imidodicarbonic acids, and R—O—C(═O)—NR′— Hydrazidodicarbonic acids,NH—C(═O)—O—R′′ for hydrazidodicarbonic acids, Bis(imidodicarbonicacids), where R, R′, and R′′ represent H, NH₂, or anyBis(hydrazidodicarbonic acids), organic functional group wherein thenumber of Poly(imidodicarbonic acids), carbon atoms ranges from 0 to 40,optionally Poly(hydrazidodicarbonic acids) and having halogen orpolarizing or water- derivatives thereof (O—O Bidentates, O—Oinsolubilizing/solubilizing groups attached. Tridentates, O—OTetradentates) Ligand can also contain nonbinding N, O, S, or P atoms. OValence Stabilizer #5: RR′—N—S(═O)(═O)—NR′′—S(═O)(═O)—NR′′′R′′′′Imidodisulfamic Acid, Imidodisulfuric for imidodisulfamic acid, andR—O—S(═O)(═O)— Acid, Bis(Imidodisulfamic Acid), NR′—S(═O)(═O)—OR′′ forimidosulfuric acid, Bis(Imidodisulfuric Acid), where R, R′, and R′′represent H, NH₂, or any Poly(Imidodisulfamic Acid), and organicfunctional group wherein the number of Poly(Imidodisulfuric Acid) andderivatives carbon atoms ranges from 0 to 40, optionally thereof (O—OBidentates, O—O Tridentates, having halogen or polarizing or water- O—OTetradentates) insolubilizing/solubilizing groups attached. Ligand canalso contain nonbinding N, O, S, or P atoms. O Valence Stabilizer #6:R—C(═O)—CR′R′′—C(═O)—R′′′ where R, R′, R′′, 1,3-Diketones(Beta-Diketonates), 1,3,5- and R′′′ represent H, NH₂, or any organicTriketones, Bis(1,3-Diketones), and functional group wherein the numberof carbon Poly(1,3-Diketones), all with a Molecular atoms ranges from 0to 40, optionally having Weight Greater than 125 (O—O Bidentates,halogen or polarizing or water- O—O Tridentates, O—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. If these ligands exhibit a molecularweight less than or equal to 125, the solubility of the resultantdiketonate complex will be too high. O Valence Stabilizer #7:R—C(═O)—C(═O)—R′ where R and R′ represent 1,2-Diketones(Alpha-Diketonates), 1,2,3- H, NH₂, or any organic functional groupTriketones, Tropolonates, ortho-Quinones, wherein the number of carbonatoms ranges Bis(1,2-Diketones), and Poly(1,2- from 0 to 40, optionallyhaving halogen or Diketones), all with a Molecular Weight polarizing orwater-insolubilizing/solubilizing Greater than 100 (O—O Bidentates, O—Ogroups attached. Ligand can also contain Tridentates, O—O Tetradentates)nonbinding N, O, S, or P atoms. If these ligands exhibit a molecularweight less than or equal to 100, the solubility of the resultantdiketonate complex will be too high. O Valence Stabilizer #8:RR′—N—C(═O)—CR′′R′′′—C(═O)—N—R′′′′R′′′′′ Malonamides (Malonodiamides),where R, R′, R′′, R′′′,R′′′′, and R′′′′′ represent H, Bis(malonamides),and Polymalonamides NH₂, or any organic functional group wherein (O—OBidentates, O—O Tridentates, O—O the number of carbon atoms ranges from0 to Tetradentates) 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. O Valence Stabilizer #9:RR′—N—C(═O)—CR′′R′′′—C(═O)—R′′′′ where R, R′, 2-Acylacetamides,Bis(2-acylacetamides), R′′, R′′′, and R′′′′ represent H, NH₂, or any andPoly(2-acylacetamides) (O—O organic functional group wherein the numberof Bidentates, O—O Tridentates, O—O carbon atoms ranges from 0 to 40,optionally Tetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #10:RR′—N—C(═O)—S—C(═O)—N—R′′R′′′ where R, R′, Monothiodicarbonic Diamides,R′′, and R′′′ represent H, NH₂ or any organic Bis(monothiodicarbonicdiamides), and functional group wherein the number of carbonPoly(monothiodicarbonic diamides) (O—O atoms ranges from 0 to 40,optionally having Bidentates, O—O Tridentates, O—O halogen or polarizingor water- Tetradentates) insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. O ValenceStabilizer #11: R—O—C(═O)—S—C(═O)—O—R′, where R and R′Monothiodicarbonic Acids, represent H, NH₂ or any organic functionalBis(monothiodicarbonic acids), group wherein the number of carbon atomsPoly(monothiodicarbonic acids), and ranges from 0 to 40, optionallyhaving halogen derivatives thereof (O—O Bidentates, O—O or polarizing orwater- Tridentates, O—O Tetradentates) insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.O Valence Stabilizer #12: R—O—S(═O)(═O)—S—S(═O)(═O)—O—R′, where RTrithionic acid, Bis(trithionic acid), and R′ represent H, NH₂ or anyorganic Poly(trithionic acid), and derivatives functional group whereinthe number of carbon thereof (O—O Bidentates, O—O Tridentates, atomsranges from 0 to 40, optionally having O—O Tetradentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#13: (R—O—)(R′—O—)P(═O)—P(═O)(—O—R′′)(—O—R′′′), Hypophosphoric Acids,where R, R′, R′′, and R′′′ represent H, NH₂ or Bis(hypophosphoricacids), and any organic functional group wherein the Poly(hypophosphoricacids), and number of carbon atoms ranges from 0 to 40, derivativesthereof (O—O Bidentates, O—O optionally having halogen or polarizing orTridentates, O—O Tetradentates) water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. Note:these ligands are not to be confused with hypophosphorous acidderivatives (hypophosphites) (R—O—) R′′R′′′P(═O) which are very reducingand therefore unacceptable for stabilization of high valence states inmetal ions. O Valence Stabilizer #14: RR′—N—)(R′′R′′′—N—)P(═O)—P(═O)(—N—Hypophosphoramides, R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′), where R, R′, R′′,R′′′, Bis(hypophosphoramides), and R′′′′, R′′′′′, R′′′′′′, and R′′′′′′′represent H, NH₂ or Poly(hypophosphoramides) (O—O any organic functionalgroup wherein the Bidentates, O—O Tridentates, O—O number of carbonatoms ranges from 0 to 40, Tetradentates) optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. Note: these ligands arenot to be confused with hypophosphorous acid derivatives(hypophosphites) (R—O—) R′′R′′′P(═O) which are very reducing andtherefore unacceptable for stabilization of high valence states in metalions. O Valence Stabilizer #15: (R—O—)(R′—O—P(═O)—NH—P(═O)(—O—R′′)(—O—Imidodiphosphoric Acids, R′′′) for imidodiphosphoric acids, and (R—O—)Hydrazidodiphosphoric Acids, (R′—O—)P(═O )—NH—NH—P(═O )(—O—R′′)(—O—R′′′)Bis(imidodiphosphoric Acids), for hydrazidodiphosphoric acids; where R,R′, Bis(hydrazidodiphosphoric Acids), R′′, and R′′′ represent H, NH₂ orany organic Poly(imidodiphosphoric Acids), functional group wherein thenumber of carbon Poly(hydrazidodiphosphoric Acids), and atoms rangesfrom 0 to 40, optionally having derivatives thereof (O—O Bidentates, O—Ohalogen or polarizing or water- Tridentates, O—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #16:(RR′—N—)(R′′R′′′—N—)P(═O)—NH—P(═O)(—N— Imidodiphosphoramides,R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′) for Hydrazidodiphosphoramides,imidodiphosphoramides, and —NH—NH— Bis(imidodiphosphoramides),derivatives for hydrazidodiphosphoramides,Bis(hydrazidodiphosphoramides), where R, R′, R′′, R′′′, R′′′′, R′′′′′,R′′′′′′, and Poly(imidodiphosphoramides), and R′′′′′′′ represent H, NH₂or any organic Poly(hydrazidodiphosphoramides) (O—O functional groupwherein the number of carbon Bidentates, O—O Tridentates, O—O atomsranges from 0 to 40, optionally having Tetradentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#17: (RR′—N—)(R′′R′′′—N—)P(═O)—O—P(═O)(—N— Diphosphoramides,Bis(diphosphoramides), R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′), where R, R′,R′′, R′′′, and Poly(diphosphoramides) (O—O R′′′′, R′′′′′, R′′′′′′, andR′′′′′′′ represent H, NH₂ or Bidentates, O—O Tridentates, O—O anyorganic functional group wherein the Tetradentates) number of carbonatoms ranges from 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. O Valence Stabilizer #18:R—CR′(—OH)—CH₂—C(═O)—R′′, where R, R′, and Beta-Hydroxyketones, Beta-R′′ represent H, NH₂ or any organic functional Hydroxyaldehydes,Bis(beta- group wherein the number of carbon atoms hydroxyketones),Bis(beta- ranges from 0 to 40, optionally having halogenhydroxyaldehydes), Poly(beta- or polarizing or water- hydroxyketones),and Poly(beta- insolubilizing/solubilizing groups attached.hydroxyaldehydes) (O—O Bidentates, O—O Ligand can also containnonbinding N, O, S, or Tridentates, O—O Tetradentates) P atoms. OValence Stabilizer #19: RR′—N—C(═O)—C(═O)—N—R′′R′′′, where R, R′,Oxamides, Bis(oxamides), and R′′, and R′′′ represent H, NH₂ or anyorganic Poly(oxamides) (O—O Bidentates, O—O functional group wherein thenumber of carbon Tridentates, O—O Tetradentates) atoms ranges from 0 to40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #20:—C(—OH)═C(—OH)—, where the two carbon atoms Squaric Acids andderivatives thereof (O—O supporting the hydroxy groups are includedBidentates) within a cyclic hydrocarbon moiety, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. OValence Stabilizer #21: (R—O—)(O═)C—R′—C(═O)(—O—R′′), where R, R′,Dicarboxylic Acids, Bis(dicarboxylic and R′′ represent H, NH₂ or anyorganic acids), Poly(dicarboxylic acids), and functional group whereinthe number of carbon derivatives thereof (O—O Bidentates and O—O atomsranges from 0 to 40, optionally having Tetradentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#22: R—O—C(═O)—O—R′, where R, and R′ represent H, Carbonates andBis(carbonates) (O—O NH₂ or any organic functional group whereinBidentates and O—O Tetradentates) the number of carbon atoms ranges from0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. O Valence Stabilizer #23:RR′N⁺═C(OH)(OH), where R and R′ represent Carbamates, Bis(carbamates),and H, OH, SH, OR′′ (R′′ = C₁-C₃₀ alkyl or aryl), Poly(carbamates)(including N- SR′′ (R′′ = C₁-C₃₀ alkyl or aryl), NH₂ or anyhydroxycarbamates and N- organic functional group wherein the number ofmercaptocarbamates) (O—O Bidentates, O—O carbon atoms ranges from 0 to40, optionally Tridentates, and O—O Tetradentates) having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#24: RN═C(OH)(OH), where R represents H, NH₂ or Carbimates,Bis(carbimates), and any organic functional group wherein thePoly(carbimates) (O—O Bidentates, O—O number of carbon atoms ranges from0 to 40, Tridentates, and O—O Tetradentates) optionally having halogenor polarizing or water-insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. O ValenceStabilizer #25: RR′—N—CH(—OH)—NR′′—C(═O)—NR′′′R′′′′, whereN-(Aminomethylol)ureas [N- R, R′, R′′, R′′′, and R′′′′ represent H, NH₂or any (Aminohydroxymethyl)ureas], Bis[N- organic functional groupwherein the number of (aminomethylol)ureas], and Poly[N- carbon atomsranges from 0 to 40, optionally (aminomethylol)ureas] (O—O Bidentates,O—O having halogen or polarizing or water- Tridentates, O—OTetradentates) insolubilizing/solubilizing groups attached. Ligand canalso contain nonbinding N, O, S, or P atoms. O Valence Stabilizer #26:Cyanates bound directly to the high valence Cyanate ligands (OMonodentates) metal ion. N—S Valence Stabilizer #1:RR′—N—C(═NH)—S—S—C(═NH)—NR′′R′′′, where Diformamidine Disulfides R, R′,R′′, and R′′′ represent H, NH₂, or any (ThioperoxydicarbonimidicDiamides or organic functional group wherein the number ofDihydrazides), Thioperoxytricarbonimidic carbon atoms ranges from 0 to40, optionally Diamides or Dihydrazides, having halogen or polarizing orwater- Thioperoxytetracarbonimidic Diamides orinsolubilizing/solubilizing groups attached. Dihydrazides,Bis(diformamidine Ligand can also contain nonbinding N, O, S, ordisulfides), and Poly(diformamidine P atoms. disulfides) (N—SBidentates, N—S Tridentates, N—S Tetradentates) N—S Valence Stabilizer#2: RR′—N—C(═NH)—S—CS—NR′′R′′′, where R, R′, S-Amidinodithiocarbamates,Bis(S- R′′, and R′′′ represent H, NH₂ or any organicamidinodithiocarbamates), and Poly(S- functional group wherein thenumber of carbon amidinodithiocarbamates) (N—S Bidentates atoms rangesfrom 0 to 40, optionally having and N—S Tetradentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#3: RR′—N—C(═NH)—O—CS—NR′′R′′′, where R, R′, O-Amidinothiocarbamates,Bis(O- R′′, and R′′′ represent H, NH₂ or any organicamidinothiocarbamates), and Poly(O- functional group wherein the numberof carbon amidinothiocarbamates) (N—S Bidentates atoms ranges from 0 to40, optionally having and N—S Tetradentates) halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #4:RR′—N—C(═NH)—S—S—CS—NR′′R′′′, where R, R′,S-Amidinoperoxythiocarbamates, Bis(S- R′′, and R′′′ represent H, NH₂ orany organic amidinoperoxythiocarbamates), and Poly(S- functional groupwherein the number of carbon amidinoperoxythiocarbamates) (N—S atomsranges from 0 to 40, optionally having Bidentates and N—S Tetradentates)halogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—SValence Stabilizer #5: (NH═)P(—SR)(—OR′)(—OR′′) for PhosphorimidothioicAcid; phosphorimidothioic acid, (NH═)P(—SR)(—SR′)(—OR′′)Phosphorimidodithioic Acid; for phosphorimidodithioic acid, (NH═)P(—Phosphorimidotrithioic Acid; SR)(—SR′)(—SR′′) for phosphorimidotrithioicBis(Phosphorimidothioic Acid); acid, where R, R′, and R′′ represent H,NH₂ or Bis(Phosphorimidodithioic Acid); any organic functional groupwherein the Bis(Phosphorimidotrithioic Acid); number of carbon atomsranges from 0 to 40, Poly(Phosphorimidothioic Acid); optionally havinghalogen or polarizing or Poly(Phosphorimidodithioic Acid);water-insolubilizing/solubilizing groups Poly(PhosphorimidotrithioicAcid); and attached. Ligand can also contain nonbinding N, derivativesthereof (N—S Bidentates and N—S O, S, or P atoms. Tetradentates) N—SValence Stabilizer #6: (S═)P(—NRR′)(—NR′′R′′′)(—NR′′′′R′′′′′), where R,Phosphorothioic Triamides, R′, R′′, R′′′, R′′′′, and R′′′′′ represent H,NH₂ or Bis(phosphorothioic triamides), and any organic functional groupwherein the Poly(phosphorothioic triamides) (N—S number of carbon atomsranges from 0 to 40, Bidentates and N—S Tetradentates) optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—SValence Stabilizer #7: (S═)P(—NRR′)(—SR′′)(—SR′′′) forPhosphoramidotrithioic Acid, phosphoramidotrithioic acid, and (S═)P(—Phosphorodiamidodithioic Acid, NRR′)(—NR′′R′′′)(—SR′′′′) forBis(phosphoramidotrithioic acid), phosphorodiamidodithioic acid, whereR, R′, Bis(phosphorodiamidodithioic acid), R′′, R′′′, and R′′′′represent H, NH₂ or any poly(phosphoramidotrithioic acid), organicfunctional group wherein the number of poly(phosphorodiamidodithioicacid), and carbon atoms ranges from 0 to 40, optionally derivativesthereof (N—S Bidentates and N—S having halogen or polarizing or water-Tetradentates) insolubilizing/solubilizing groups attached. Ligand canalso contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #8:(O═)P(—NRR′)(—SR′′)(—OR′′′) or (S═)P(— Phosphoramidothioic Acid,NRR′)(—OR′′)(—OR′′′) for phosphoramidothioic Phosphoramidodithioic Acid,acid; (O═)P(—NRR′)(—SR′′)(—SR′′′) or (S═)P(— PhosphorodiamidothioicAcid, NRR′)(—SR′′)(—OR′′′) for Bis(Phosphoramidothioic Acid),phosphoramidodithioic acid; (O═)P(—NRR′)(— Bis(PhosphoramidodithioicAcid), NR′′R′′′)(—SR′′′′) or (S═)P(—NRR′)(—NR′′R′′′)(—OR′′′′)Bis(Phosphorodiamidothioic Acid), for phosphorodiamidothioic acid, wherePoly(Phosphoramidothioic Acid), R, R′, R′′, R′′′, and R′′′′ represent H,NH₂ or any Poly(Phosphoramidodithioic Acid), and organic functionalgroup wherein the number of Poly(Phosphorodiamidothioic Acid) (N—Scarbon atoms ranges from 0 to 40, optionally Bidentates and N—STetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #9:R′—C(═S)—N═C(—R)(—NHR′′), where R is an N-Thioacyl7-Aminobenzylidenimines (N—S aromatic derivative (i.e., —C₆H₅), and R′and R′′ Bidentates or N—S Tetradentates) represent H, NH₂, or anyorganic functional group wherein the number of carbon atoms ranges from0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #10:R—C(═S)—NR′—OH or R—C(—SH)═N—OH, where Thiohydroxamates(Thiohydroxylamines), R and R′ represent H, NH₂, or any organicBis(thiohydroxamates), and functional group wherein the number of carbonPoly(thiohydroxamates) (N—S Bidentates, atoms ranges from 0 to 40,optionally having N—S Tetradentates, and N—S Hexadentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#11: R—CH(—NHR′)—C(═S)(—OH) or R—CH(—NHR′)— Alpha- orortho-Aminothiocarboxylic C(═S)(—SH) for aminothiocarboxylic acids, andAcids, and alpha- or ortho- (HO—)(S═)C—CH(—NHR)—R′—CH(—NHR′′)—Aminothiodicarboxylic Acids, and C(═S)(—OH) or (HS—)(S═)C—CH(—NHR)—R′—derivatives thereof (N—S Bidentates, N—S CH(—NHR′′)—C(═S)(—SH) forTridentates, and N—S Tetradentates) aminothiodicarboxylic acids, whereR, R′, and R′′ represent any organic functional group wherein the numberof carbon atoms ranges from 1 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#12: RR′—N—C(═S)—NR′′—N═CR′′′R′′′′, where R, R′, Thiosemicarbazones,R′′, R′′′, and R′′′′ represent H, or any organicBis(thiosemicarbazones), and functional group wherein the number ofcarbon Poly(thiosemicarbazones) (N—S Bidentates, atoms ranges from 0 to40, optionally having N—S Tetradentates, and N—S Hexadentates) halogenor polarizing or water- insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. N—S ValenceStabilizer #13: R—C(═S)—NR′—N═CR′′R′′′, where R, R′, R′′, and Thioacylhydrazones, Bis(thioacyl R′′′ represent H, or any organic functionalhydrazones), and Poly(thioacyl hydrazones) group wherein the number ofcarbon atoms (N—S Bidentates, N—S Tetradentates, and N—S ranges from 0to 40, optionally having halogen Hexadentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #14:R—N═N—C(═S)—NR′—NR′′R′′′, where R, R′, R′′, Thiocarbazones(Diazenecarbothioic and R′′′ represent H, or any organic functionalhydrazides), Bis(thiocarbazones), and group wherein the number of carbonatoms Poly(thiocarbazones) (N—S Bidentates, N—S ranges from 0 to 40,optionally having halogen Tetradentates, and N—S Hexadentates) orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#15: R—N═N—R′ for azo compounds, R—N═N—NH—R′ Azo compounds includingtriazenes with for triazenes, where R, and R′ represent H or thiol ormercapto or thiocarbonyl any organic functional group wherein thesubstitution at the ortho- (for aryl) or alpha- number of carbon atomsranges from 0 to 40, or beta- (for alkyl) positions, Bis[o-(HS—) oroptionally having halogen or polarizing or alpha- or beta-(HS—)azocompounds], or water-insolubilizing/solubilizing groups Poly[o-(HS—) oralpha- or beta-(HS—)azo attached. (Must include ortho-thio, mercapto, orcompounds) (N—S Bidentates, N—S thiocarbonyl substituted aryl azocompounds, Tridentates, N—S Tetradentates, or N—S and alpha- orbeta-thio, mercapto, or Hexadentates) thiocarbonyl alkyl azo compounds.)Ligand can also contain nonbinding N, O, S, or P atoms. N—S ValenceStabilizer #16: R—N═N—C(═S)—NR′R′′ for Diazeneformothioamides,diazeneformothioamides, and R—N═N—CR′R′′— Diazeneacetothioamides,C(═S)—NR′′′R′′′′ for diazeneacetothioamides,Bis(diazeneformothioamides), where R, R′, R′′, R′′′, and R′′′′ representH, Bis(diazeneacetothioamides), NH₂, or any organic functional groupwherein Poly(diazeneformothioamides), and the number of carbon atomsranges from 0 to Poly(diazeneacetothioamides) (N—S 40, optionally havinghalogen or polarizing or Bidentates, N—S Tetradentates, and N—Swater-insolubilizing/solubilizing groups Hexadentates) attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#17: R—N═N—C(═S)—O—R′ or R—N═N—CR′R′′—C(═S)— Diazenecarbothioic acids,O—R′′′ for diazenecarbothioic acids, and R— Diazenecarbodithioic acids,N═N—C(═S)—S—R′ or R—N═N—CR′R′′—C(═S)—S—R′′′ Bis(diazenecarbothioicacids), for diazenecarbodithoic acids, where R, R′,Bis(diazenecarbodithioic acids), R′′, and R′′′ represent H, NH₂, or anyorganic Poly(diazenecarbothioic acids), functional group wherein thenumber of carbon Poly(diazenecarbodithioic acids) and atoms ranges from0 to 40, optionally having derivatives thereof (N—S Bidentates, N—Shalogen or polarizing or water- Tetradentates, N—S Hexadentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #18:R—N═N—C(═S)—R′ for Diazeneformothioaldehydes, diazeneformothioaldehydes,and R—N═N— Diazeneacetothioaldehydes, CR′R′′—C(═S)—R′′′ forBis(diazeneformothioaldehydes), diazeneacetothioaldehydes, where R, R′,R′′, Bis(diazeneacetothioaldehydes), and R′′′ represent H, NH₂, or anyorganic Poly(diazeneformothioaldehydes), and functional group whereinthe number of carbon Poly(diazeneacetothioaldehydes) (N—S atoms rangesfrom 0 to 40, optionally having Bidentates, N—S Tetradentates and N—Shalogen or polarizing or water- Hexadentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #19:RR′—N—C(═S)—N═N—C(═S)—NR′′R′′′ or RR′—N— Diazenediformothioamides,C(═S)—N═N—C(═O)—NR′′R′′′ for Diazenediacetothioamides,diazenediformothioamides, and RR′—N—C(═S)—Bis(diazenediformothioamides),CR′′R′′′—N═N—CR′′′′R′′′′′—C(═S)—NR′′′′′′R′′′′′′′ orBis(diazenediacetothioamides),RR′—N—C(═S)—CR′′R′′′—N═N—CR′′′′R′′′′′—C(═O)—Poly(diazenediformothioamides), and NR′′′′′′R′′′′′′′ fordiazenediacetothioamides, Poly(diazenediacetothioamides) (N—S where R,R′, R′′, R′′′, R′′′′, R′′′′′, R′′′′′′, and Tridentates and N—SHexadentates) R′′′′′′′ represent H, NH₂, or any organic functional groupwherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.N—S Valence Stabilizer #20: R—O—C(═S)—N═N—C(═S)—O—R′, R—O—C(═S)—Diazenedicarbothioic acids, CR′R′′—N═N—CR′′′R′′′′—C(═S)—O—R′′′′′, R—O—Diazenedicarbodithioic acids, C(═S)—N═N—C(═O)—O—R′, or R—O—C(═S)—Bis(diazenedicarbothioic acids), CR′R′′—N═N—CR′′′R′′′′—C(═O)—O—R′′′′′for Bis(diazenedicarbodithioic acids), diazenedicarbothioic acids, andR—S—C(═S)— Poly(diazenedicarbothioic acids), N═N—C(═S)—S—R′ orR—S—C(═S)—CR′R′′—N═N— Poly(diazenedicarbodithioic acids) andCR′′′R′′′′—C(═S)—S—R′′′′′ for derivatives thereof (N—S Tridentates anddiazenedicarbodithoic acids, where R, R′, R′′, N—S Hexadentates) R′′′,R′′′′, and R′′′′′ represent H, NH₂, or any organic functional groupwherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.N—S Valence Stabilizer #21: RC(═S)—N═N—C(═S)—R′ or RC(═S)—N═N—Diazenediformothioaldehydes, C(═O)—R′ for diazenediformothioaldehydes,and Diazenediacetothioaldehydes,RC(═S)—CR′R′′—N═N—CR′′′R′′′′—C(═S)—R′′′′′ orBis(diazenediformothioaldehydes),RC(═S)—CR′R′′—N═N—CR′′′R′′′′—C(═O)—R′′′′′ forBis(diazenediacetothioaldehydes), diazenediacetothioaldehydes, where R,R′, R′′, Poly(diazenediformothioaldehydes), and R′′′, R′′′′, and R′′′′′represent H, NH₂, or any Poly(diazenediacetothioaldehydes) (N—S organicfunctional group wherein the number of Tridentates and N—S Hexadentates)carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#22: R—N═N—CR′═N—NR′′R′′′, where R, R′, R′′, and Ortho-thio (or-mercapto) Substituted R′′′ represent H, or any organic functionalFormazans, Bis(o-thio or -mercapto group wherein the number of carbonatoms substituted formazans), and Poly(o-thio or ranges from 0 to 40,optionally having halogen -mercapto substituted formazans) (N—S orpolarizing or water- Bidentates, N—S Tridentates, N—Sinsolubilizing/solubilizing groups attached. Tetradentates, and N—SHexadentates) (Must include ortho-thio or mercapto substituted aryl Rderivatives, and beta-thio or mercapto substituted alkyl R derivatives.)Ligand can also contain nonbinding N, O, S, or P atoms. N—S ValenceStabilizer #23: RR′C═N—N═CR′′R′′′ or RR′C═N—NR′′R′′′ (for Ortho-thio (or-mercapto) Substituted ketazines), where R, R′, R′′, and R′′′ representAzines (including ketazines), Bis(o-thio or H, or any organic functionalgroup wherein the mercapto substituted azines), and Poly(o- number ofcarbon atoms ranges from 0 to 40, thio or mercapto substituted azines)(N—S optionally having halogen or polarizing or Bidentates, N—STridentates, N—S water-insolubilizing/solubilizing groups Tetradentates,and N—S Hexadentates) attached. (Must include ortho-thio or mercaptosubstituted aryl R derivatives, and beta-thio or mercapto substitutedalkyl R derivatives.) Ligand can also contain nonbinding N, O, S, or Patoms. N—S Valence Stabilizer #24: RR′C═N—R′′, where R, R′, and R′′represent H, Schiff Bases with one Imine (C═N) Group or any organicfunctional group wherein the and with ortho- or alpha- or beta-thio ornumber of carbon atoms ranges from 0 to 40, mercapto or thiocarbonylsubstitution (N—S optionally having halogen or polarizing or Bidentates,N—S Tridentates, N—S water-insolubilizing/solubilizing groupsTetradentates, N—S Pentadentates, or N—S attached. (Must contain ortho-or alpha- or beta- Hexadentates). Also includes Schiff Bases thio ormercapto or thiocarbonyl substitution.) derived from the reaction ofcarbonyl Ligand can also contain nonbinding N, O, S, or compounds withdithiocarbazates, and P atoms. hydrazones with ortho-S substitution. N—SValence Stabilizer #25: RR′C═N—R′′—N═CR′′′R′′′′ or R—N═C—R′—C═N—R′Schiff Bases with two Imine (C═N) Groups or RC═N—R′—N═CR′′, where R, R′,R′′, R′′′, and with ortho- or alpha- or beta-thio or and R′′′′ representH, or any organic functional mercapto or thiocarbonyl substitution (N—Sgroup wherein the number of carbon atoms Tridentates, N—S Tetradentates,N—S ranges from 0 to 40, optionally having halogen Pentadentates, or N—SHexadentates). or polarizing or water- Also includes Schiff Basesderived from the insolubilizing/solubilizing groups attached. reactionof carbonyl compounds with (Must contain ortho- or alpha- or beta-thioor dithiocarbazates, and hydrazones with mercapto or thiocarbonylsubstitution.) Ligand ortho-S substitution. can also contain nonbindingN, O, S, or P atoms. N—S Valence Stabilizer #26: N(—R—N═CR′R′′)₃, whereR, R′, and R′′ Schiff Bases with three Imine (C═N) represent H, or anyorganic functional group Groups and with ortho- or alpha- or beta-wherein the number of carbon atoms ranges thio or mercapto orthiocarbonyl from 0 to 40, optionally having halogen or substitution(N—S Tetradentates, N—S polarizing or water-insolubilizing/solubilizingPentadentates, or N—S Hexadentates). groups attached. (Must containortho- or alpha- Also includes Schiff Bases derived from the orbeta-thio or mercapto or thiocarbonyl reaction of carbonyl compoundswith substitution.) Ligand can also contain dithiocarbazates, andhydrazones with nonbinding N, O, S, or P atoms. ortho-S substitution.N—S Valence Stabilizer #27: [R—CR′(—NR′′R′′′)]_(x)—R′′′′—[C(— ThioalkylAmines (Aminothiols or SR′′′′′)R′′′′′′R′′′′′′′]_(y),[R—CR′(—NR′′R′′′)]_(x)—R′′′′— Aminodisulfides) and Thioalkyl Imines[C(—S—S—R′′′′′)R′′′′′′R′′′′′′′]_(y), or [R—CR′(— (Iminothiols orIminodisulfides) (N—S NR′′R′′′)]_(x)—R′′′′—C(═S)R′′′′′]_(y) forthioalkyl Bidentates, N—S Tridentates, N—S amines; and[R—C(═NR′)]_(x)—R′′—[C(— Tetradentates, and N—S Hexadentates)SR′′′)R′′′′R′′′′′]_(y), [R—C(═NR′)]_(x)—R′′—[C(—S—SR′′′)R′′′′R′′′′′]_(y), or [R—C(═NR′)]_(x)—R′′— [C(═S)R′′′]_(y) forthioalkyl imines, where R, R′, R′′, R′′′, R′′′′, R′′′′′, R′′′′′′, andR′′′′′′′ represent H, NH₂, or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached, and xand y = 1-6. Ligand can also contain inenonbinding N, O, S, or P atoms.N—S Valence Stabilizer #28: [R(—NR′R′′)(—SR′′′)],[R(—NR′R′′)(—S—S—R′′′)], Thioaryl Amines and Thioaryl Imines (N—S[R(—NR′R′′)(—C(═S)R′′′], [R(—NR′R′′)_(x)]₂S, Bidentates, N—STridentates, N—S [R(—NR′R′′)_(x)]₂₋₃R′′′(—SR′′′′)_(y),[R(—SR′)_(x)]₂₋₃R′′ Tetradentates, and N—S Hexadentates)(—NR′′′R′′′′)_(y), [R(—NR′R′′)_(x)]₂S₂, and[R(—NR′R′′)_(x)]₂R′′′(C(═S))_(y)R′′′′ for thioaryl amines; and[R(—SR′)_(x)]₂NH or [R(—SR′)_(x)]₂NHNH for thioaryl imines, where R, R′,R′′, R′′′, and R′′′′ represent H, NH₂, or any organic functional groupwherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached, and x = 0-2 and y = 1-4. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #29: Fivemembered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one, two, three, or four nitrogen atoms. In containing One, Two,Three, or Four addition, ligand contains additional sulfur- NitrogenAtoms at least one additional containing substituents (usually thiols,Sulfur Atom Binding Site not in a Ring (N—S mercaptans, disulfides, orthiocarbonyls) that Bidentates, N—S Tridentates, N—S constitute Sbinding sites. Can include other Tetradentates, or N—S Hexadentates)ring systems bound to the heterocyclic ring or to the S-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. This5-membered ring(s) and/or attached, uncoordinating rings and/or S-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N—S ValenceStabilizer #30: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one, two, three, or four nitrogen atoms.In containing One, Two, Three, or Four addition, ligand containsadditional sulfur- Nitrogen Atoms at least one additional containingsubstituents (usually thiols, Sulfur Atom Binding Site not in a Ring(N—S mercaptans, disulfides, or thiocarbonyls) that Bidentates, N—STridentates, N—S constitute S binding sites. Can include otherTetradentates, or N—S Hexadentates) ring systems bound to theheterocyclic ring or to the S-containing substituent, but they do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, S, or P atoms. This 6-membered ring(s) and/or attached,uncoordinating rings and/or S- containing substituent(s) may or may nothave halogen or polarizing or water- insolubilizing/solubilizing groupsattached. N—S Valence Stabilizer #31: Five membered heterocyclic ring(s)containing Five-Membered Heterocyclic Rings one or two sulfur atoms. Inaddition, ligand containing One or Two Sulfur Atoms at containsadditional nitrogen-containing least one additional Nitrogen AtomBinding substituents (usually amines, imines, or Site not in a Ring (N—SBidentates, N—S hydrazides) that constitute N binding sites. CanTridentates, N—S Tetradentates, or N—S include other ring systems boundto the Hexadentates) heterocyclic ring or to the N-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. This5-membered ring(s) and/or attached, uncoordinating rings and/orN-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N—S ValenceStabilizer #32: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one or two sulfur atoms. In addition,ligand containing One or Two Sulfur Atoms at contains additionalnitrogen-containing least one additional Nitrogen Atom Bindingsubstituents (usually amines, imines, or Site not in a Ring (N—SBidentates, N—S hydrazides) that constitute N binding sites. CanTridentates, N—S Tetradentates, or N—S include other ring systems boundto the Hexadentates) heterocyclic ring or to the N-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. This6-membered ring(s) and/or attached, uncoordinating rings and/orN-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N—S ValenceStabilizer #33: Five membered heterocyclic ring(s) containingFive-Membered Heterocyclic Rings one, two, three, or four nitrogenatoms. In containing One, Two, Three, or Four addition, ligand containsadditional sulfur- Nitrogen Atoms at least one additional containingrings that constitute S binding sites. Sulfur Atom Binding Site in aSeparate Can include other ring systems bound to the N- Ring (N—SBidentates, N—S Tridentates, N—S or S-containing heterocyclic rings, butthey do Tetradentates) not coordinate with the stabilized, high valencemetal ion. Ring(s) can also contain O, S, or P atoms. This 5-memberedring(s) and/or additional S-containing ring(s) and/or attached,uncoordinating rings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. N—S Valence Stabilizer #34:Six membered heterocyclic ring(s) containing Six-Membered HeterocyclicRings one, two, three, or four nitrogen atoms. In containing One, Two,Three, or Four addition, ligand contains additional sulfur- NitrogenAtoms at least one additional containing rings that constitute S bindingsites. Sulfur Atom Binding Site in a Separate Can include other ringsystems bound to the N- Ring (N—S Bidentates, N—S Tridentates, N—S orS-containing heterocyclic rings, but they do Tetradentates) notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, S, or P atoms. This 6-membered ring(s) and/or additionalS-containing ring(s) and/or attached, uncoordinating rings may or maynot have halogen or polarizing or water- insolubilizing/solubilizinggroups attached. N—S Valence Stabilizer #35: Macrocyclic ligandscontaining two, three, four, Two-, Three-, Four-, Six-, Eight-, and Ten-six, eight, or ten binding sites composed of Membered Macrocyclics,Macrobicyclics, nitrogen and sulfur to valence stabilize the andMacropolycyclics (including central metal ion. Can include otherCatapinands, Cryptands, Cyclidenes, and hydrocarbon or ring systemsbound to this Sepulchrates) wherein all Binding Sites are macrocyclicligand, but they do not coordinate composed of Nitrogen (usually amineor with the stabilized, high valence metal ion. This imine groups) orSulfur (usually thiols, ligand and/or attached, uncoordinatingmercaptans, or thiocarbonyls) and are not hydrocarbons/rings may or maynot have contained in Component Heterocyclic halogen or polarizing orwater- Rings (N—S Bidentates, N—S Tridentates, N—Sinsolubilizing/solubilizing groups attached. Tetradentates, and N—SHexadentates) N—S Valence Stabilizer #36: Macrocyclic ligands containinga total of four, Four-, Six-, Eight-, or Ten- Membered six, eight, orten heterocyclic rings containing Macrocyclics, Macrobicyclics, andnitrogen or sulfur binding sites. Can include Macropolycyclics(including Catapinands, other hydrocarbon/ring systems bound to thisCryptands, Cyclidenes, and Sepulchrates) macrocyclic ligand, but they donot coordinate wherein all Binding Sites are composed of with thestabilized, high valence metal ion. This Nitrogen or Sulfur and arecontained in ligand and/or attached, uncoordinating ComponentHeterocyclic Rings (N—S hydrocarbon/rings may or may not have halogenBidentates, N—S Tridentates, N—S or polarizing or water-insolubilizinggroups Tetradentates, or N—S Hexadentates) attached. N—S ValenceStabilizer #37: Macrocyclic ligands containing at least one Four-, Six-,Eight-, or Ten- Membered heterocyclic ring. These heterocyclic ringsMacrocyclics, Macrobicyclics, and provide nitrogen or sulfur bindingsites to Macropolycyclics (including Catapinands, valence stabilize thecentral metal ion. Other Cryptands, Cyclidenes, and Sepulchrates) amine,imine, thiol, mercapto, or thiocarbonyl wherein all Binding Sites arecomposed of binding sites can also be included in the Nitrogen or Sulfurand are contained in a macrocyclic ligand, so long as the total numberCombination of Heterocyclic Rings and of binding sites is four, six,eight, or ten. Can Amine, Imine, Thiol, Mercapto, or include otherhydrocarbon/ring systems bound Thiocarbonyl Groups (N—S Bidentates, N—Sto this macrocyclic ligand, but they do not Tridentates, N—STetradentates, or N—S coordinate with the stabilized, high valenceHexadentates) metal ion. This ligand and/or attached, uncoordinatinghydrocarbon/rings may or may not have halogen or polarizing or water-insolubilizing groups attached. N—O Valence Stabilizer #1:R′—N(—OH)—C(—R)═N—R′′, where R, R′, and R′′ N-Hydroxy (orN,N′-dihydroxy)amidines represent H or any organic functional group andN-Hydroxy (or N,N′- wherein the number of carbon atoms rangesdihydroxy)diamidines (N—O Bidentates, N—O from 0 to 40, optionallyhaving halogen or Tridentates, or N—O Tetradentates) polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #2:RR′—N—C(═NH)—NR′′—CO—NR′′′R′′′′ for Guanylureas, Guanidinoureas,guanylureas, and RR′—N—C(═NH)—NR′′—NH—CO— Bis(guanylureas),Bis(guanidinoureas), NR′′′R′′′′ for guanidinoureas, where R, R′, R′′,Poly(guanylureas), and R′′′, and R′′′′ represent H, NH₂, or any organicPoly(guanidinoureas) (N—O Bidentates and functional group wherein thenumber of carbon N—O Tetradentates) atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #3:RR′—N—C(═NH)—NR′′—CO—R′′′ for N- Amidinoamides, Guanidinoamides,amidinoamides, or RR′—N—C(═NH)—CR′′R′′′— Bis(amidinoamides),Bis(guanidinoamides), CO—N—R′′′′R′′′′′ for 2-amidinoacetamides, andPoly(amidinoamides), and RR′—N—C(═NH)—NR′′—NH—CO—R′′′ forPoly(guanidinoamides) (including both N- guanidinoamides, where R, R′,R′′, R′′′, R′′′′, amidinoamides and 2-amidinoacetamides) and R′′′′′represent H, NH₂, or any organic (N—O Bidentates and N—O Tetradentates)functional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #4:R—C(═NH)—NR′—CO—R′′, where R, R′, and R′′, Imidoylamides,Bis(imidoylamides), and represent H or any organic functional groupPoly(imidoylamides) (N—O Bidentates and wherein the number of carbonatoms ranges N—O Tetradentates) from 0 to 40, optionally having halogenor polarizing or water-insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. N—O ValenceStabilizer #5: RR′—N—C(═NH)—O—CO—NR′′R′′′, where R, R′,O-Amidinocarbamates, Bis(O- R′′, and R′′′ represent H, NH₂, or anyorganic amidinocarbamates), and Poly(O- functional group wherein thenumber of carbon amidinocarbamates) (N—O Bidentates and atoms rangesfrom 0 to 40, optionally having N—O Tetradentates) halogen or polarizingor water- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #6:RR′—N—C(═NH)—S—CO—NR′′R′′′, where R, R′, S-Amidinothiocarbamates, Bis(S-R′′, and R′′′ represent H, NH₂, or any organic amidinothiocarbamates),and Poly(S- functional group wherein the number of carbonamidinothiocarbamates) (N—O Bidentates atoms ranges from 0 to 40,optionally having and N—O Tetradentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #7:(NH═)(NH═)P(OR)(OR′), where R, R′, and R′′ Diimidosulfuric Acid,Bis(diimidosulfuric represent H, NH₂, or any organic functional acid),and derivatives thereof (N—O group wherein the number of carbon atomsBidentates and N—O Tetradentates) ranges from 0 to 40, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #8: (NH═)P(—OR)(—OR′)(—OR′′), where R, R′, andPhosphorimidic Acid, Bis(phosphorimidic R′′ represent H, NH₂, or anyorganic functional acid); and Poly(phosphorimidic acid), and groupwherein the number of carbon atoms derivatives thereof (N—O Bidentates)ranges from 0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #9:(O═)P(—NRR′)(—NR′′R′′′)(—NR′′′′R′′′′′), where R, Phosphoric Triamides,Bis(phosphoric R′, R′′, R′′′, R′′′′, and R′′′′′ represent H, NH₂, ortriamides), and Poly(phosphoric triamides) any organic functional groupwherein the (N—O Bidentates and N—O Tetradentates) number of carbonatoms ranges from 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #10:(O═)P(—NRR′)(—OR′′)(—OR′′′) for Phosphoramidic Acid, Phosphorodiamidicphosphoramidic acid and (O═)P(—NRR′) Acid, Bis(phosphoramidic acid),(—NR′′R′′′)(—OR′′′′) for phosphorodiamidic acid, Bis(phosphorodiamidicacid), where R, R′, R′′, R′′′, and R′′′′ represent H,Poly(phosphoramidic acid), NH₂, or any organic functional group whereinPoly(phosphorodiamidic acid), and the number of carbon atoms ranges from0 to derivatives thereof (N—O Bidentates and N—O 40, optionally havinghalogen or polarizing or Tetradentates)water-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #11:R′—C(O═)—N═C(—R)(—NHR′′), where R is an N-Acyl 7-Aminobenzylidenimines(N—O aromatic derivative (i.e., —C₆H₅), and R′ and R′′ Bidentates or N—OTetradentates) represent H, NH₂, or any organic functional group whereinthe number of carbon atoms ranges from 0 to 40, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #12: R—C(═NOH)—R′ for oximes, and R—C(═NOH)— Oximes,Dioximes, and Poly(oximes) (N—O C(═NOH)—R′ for dioximes, where R and R′Bidentates, N—O Tridentates, and N—O represent H, NH₂, or any organicfunctional Tetradentates) group wherein the number of carbon atomsranges from 0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #13:R—C(═O)—C(═NOH)—R′, where R and R′ Carbonyl oximes, Bis(carbonyloximes), represent H, NH₂, or any organic functional and Poly(carbonyloximes) (N—O group wherein the number of carbon atoms Bidentates, N—OTridentates, and N—O ranges from 0 to 40, optionally having halogenTetradentates) or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.N—O Valence Stabilizer #14: R—C(═N—R′′)—C(═NOH)—R′, where R, R′, andImine oximes, Bis(imine oximes), and R′′ represent H, NH₂, or anyorganic functional Poly(imine oximes) (including 2-nitrogen groupwherein the number of carbon atoms heterocyclic oximes) (N—O Bidentates,N—O ranges from 0 to 40, optionally having halogen Tridentates, N—OTetradentates, and N—O or polarizing or water- Hexadentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #15:R—CH(—OH)—C(═NOH)—R′, where R, R′, and R′′ Hydroxy oximes, Bis(hydroxyoximes), and represent H, NH₂, or any organic functional Poly(hydroxyoximes) (including 2-oxygen group wherein the number of carbon atomsheterocyclic oximes) (N—O Bidentates, N—O ranges from 0 to 40,optionally having halogen Tridentates, N—O Tetradentates, and N—O orpolarizing or water- Hexadentates) insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #16: RR′—C(—NH—R′′)—C(═NOH)—R′′′, where R, R′, Aminooximes, Bis(amino oximes), and R′′, and R′′′ represent H, NH₂, or anyorganic Poly(amino oximes) (N—O Bidentates, N—O functional group whereinthe number of carbon Tridentates, N—O Tetradentates, and N—O atomsranges from 0 to 40, optionally having Hexadentates) halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer#17: RR′—N—C(═NOH)—R′′, where R, R′, and R′′ Amido oximes, Bis(amidooximes), and represent H, NH₂, or any organic functional Poly(amidooximes) (N—O Bidentates, N—O group wherein the number of carbon atomsTridentates, N—O Tetradentates, and N—O ranges from 0 to 40, optionallyhaving halogen Hexadentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #18:R—N═N—C(═NOH)—R′ or RR′C═N—NR′′— Azo oximes, Bis(azo oximes), andPoly(azo C(═NOH)—R′′′, where R, R′, R′′, and R′′′ oximes) (N—OBidentates, N—O Tridentates, represent H, NH₂, or any organic functionalN—O Tetradentates, and N—O Hexadentates). group wherein the number ofcarbon atoms Also includes hydrazone oximes. ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. (R is typically an arylgroup.) Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #19: o-(ON—)(HO—)Ar, where Ar represents an2-Nitrosophenols (0-Quinone monoximes) aromatic group or heterocyclicwherein the (N—O Bidentates) number of carbon atoms ranges from 6 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #20:o-(O₂N—)(HO—)Ar, where Ar represents an 2-Nitrophenols (N—O Bidentates)aromatic group or heterocyclic wherein the number of carbon atoms rangesfrom 6 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #21:R—C(═O)—NR′—OH or R—C(—OH)═N—OH, where Hydroxamates (Hydroxylamines), Rand R′ represent H, NH₂ , or any organic Bis(hydroxamates), andfunctional group wherein the number of carbon Poly(hydroxamates) (N—OBidentates, N—O atoms ranges from 0 to 40, optionally havingTetradentates, and N—O Hexadentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #22: R—N(—NO)—OH,where R represents any organic N-Nitrosohydroxylamines, Bis(N-functional group wherein the number of carbon nitrosohydroxylamines),and Poly(N- atoms ranges from 1 to 40, optionally havingnitrosohydroxylamines) (N—O Bidentates, halogen or polarizing or water-N—O Tetradentates, and N—O Hexadentates) insolubilizing/solubilizinggroups attached. (R is typically an aryl or heterocyclic group.) Ligandcan also contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer#23: R—CH(—NHR′)—C(═O)(—OH) for amino acids and Amino Acids andortho-Aminocarboxylic ortho-aminocarboxylic acids, and R—CH(—NHR′)—Acids, Peptides, Polypeptides, and ProteinsC(═O)—(NR′′—)CH(—R′′′)—C(═O)(—OH) [N—O Bidentates, N—O Tridentates, andN—O for peptides, where R, R′, R′′, and R′′′ represent Tetradentates;possibly S—O dentates for any organic functional group wherein thesulfur-contg. examples such as number of carbon atoms ranges from 1 to40, penicillamine and cystine] optionally having halogen or polarizingor water-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #24:RCONR′R′′, where R, R′, and R′′ represent H, Amides, Bis(amides), andPoly(amides), NH₂, or any organic functional group wherein includinglactams (N—O Bidentates, N—O the number of carbon atoms ranges from 0 toTridentates, and N—O Tetradentates) 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer#25: RR′—N—C(═O)—NR′′—N═CR′′′R′′′′, where R, R′, Semicarbazones,Bis(semicarbazones), and R′′, R′′′, and R′′′′ represent H, or anyorganic Poly(semicarbazones) (N—O Bidentates, N—O functional groupwherein the number of carbon Tetradentates, and N—O Hexadentates) atomsranges from 0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #26:R—C(═O)—NR′—N═CR′′R′′′, where R, R′, R′′, and Acyl hydrazones, Bis(acylhydrazones), and R′′′ represent H, or any organic functional Poly(acylhydrazones) (N—O Bidentates, N—O group wherein the number of carbonatoms Tetradentates, and N—O Hexadentates) ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #27:R—N═N—C(═O)—NR′—N—R′′R′′′, where R, R′, R′′, Carbazones(Diazenecarboxylic and R′′′ represent H, or any organic functionalhydrazides), Bis(carbazones), and group wherein the number of carbonatoms Poly(carbazones) (N—O Bidentates, N—O ranges from 0 to 40,optionally having halogen Tetradentates, and N—O Hexadentates) orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer#28: R—N═N—R′ for azo compounds, R—N═N—NH—R′ Azo compounds includingtriazenes with for triazenes, where R, and R′ represent H or hydroxyl orcarboxy or carbonyl any organic functional group wherein thesubstitution at the ortho- (for aryl) or alpha- number of carbon atomsranges from 0 to 40, or beta- (for alkyl) positions, Bis[o-(HO—)optionally having halogen or polarizing or or alpha- or beta-(HO—)azocompounds], or water-insolubilizing/solubilizing groups Poly[o-(HO—) oralpha- or beta-(HO—)azo attached. (Must include ortho-hydroxy orcompounds) (N—O Bidentates, N—O carboxy or carbonyl substituted aryl azoTridentates, N—O Tetradentates, or N—O compounds, and alpha- orbeta-hydroxy or Hexadentates) carboxy or carbonyl alkyl azo compounds.)Ligand can also contain nonbinding N, O, S, or P atoms. N—O ValenceStabilizer #29: R—N═N—C(═O)—NR′R′′ for diazeneformamides,Diazeneformamides, Diazeneacetamides, and R—N═N—CR′R′′—C(═O)—NR′′′R′′′′for Bis(diazeneformamides), diazeneacetamides, where R, R′, R′′, R′′′,and Bis(diazeneacetamides), R′′′′ represent H, NH₂, or any organicfunctional Poly(diazeneformamides), and group wherein the number ofcarbon atoms Poly(diazeneacetamides) (N—O Bidentates, ranges from 0 to40, optionally having halogen N—O Tetradentates, and N—O Hexadentates)or polarizing or water- insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. N—O ValenceStabilizer #30: R—N═N—C(═O)—O—R′ for diazeneformic acid, Diazeneformicacids, Diazeneacetic acids, and R—N═N—CR′R′′—C(═O)—O—R′′′ forBis(diazeneformic acids), Bis(diazeneacetic diazeneacetic acid, where R,R′, R′′, and R′′′ acids), Poly(diazeneformic acids), represent H, NH₂,or any organic functional Poly(diazeneacetic acids), and derivativesgroup wherein the number of carbon atoms thereof (N—O Bidentates, N—Oranges from 0 to 40, optionally having halogen Tetradentates, N—OHexadentates) or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #31: R—N═N—C(═O)—R′ for diazeneformaldehydes,Diazeneformaldehydes, and R—N═N—CR′R′′—C(═O)—R′′′ forDiazeneacetaldehydes, diazeneacetaldehydes, where R, R′, R′′, and R′′′Bis(diazeneformaldehydes), represent H, NH₂, or any organic functionalBis(diazeneacetaldehydes), group wherein the number of carbon atomsPoly(diazeneformaldehydes), and ranges from 0 to 40, optionally havinghalogen Poly(diazeneacetaldehydes) (N—O or polarizing or water-Bidentates, N—O Tetradentates and N—O insolubilizing/solubilizing groupsattached. Hexadentates) Ligand can also contain nonbinding N, O, S, or Patoms. N—O Valence Stabilizer #32: RR′—N—C(═O)—N═N—C(═O)—NR′′R′′′ forDiazenediformamides, diazenediformamides, and RR′—N—C(═O)—Diazenediacetamides, CR′′R′′′—N═N—CR′′′′R′′′′′—C(═O)—NR′′′′′′R′′′′′′′Bis(diazenediformamides), for diazenediacetamides, where R, R′, R′′,R′′′, Bis(diazenediacetamides), R′′′′, R′′′′′, R′′′′′′, and R′′′′′′′represent H, NH₂, Poly(diazenediformamides), and or any organicfunctional group wherein the Poly(diazenediacetamides) (N—O number ofcarbon atoms ranges from 0 to 40, Tridentates and N—O Hexadentates)optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #33:R—O—C(═O)—N═N—C(═O)—O—R′ for Diazenediformic acids, Diazenediaceticdiazenediformic acid, and R—O—C(═O)—CR′R′′— acids, Bis(diazenediformicacids), N═N—CR′′′R′′′′—C(═O)—O—R′′′′′ for Bis(diazenediacetic acids),diazenediacetic acid, where R, R′, R′′, R′′′, R′′′′,Poly(diazenediformic acids), and R′′′′′ represent H, NH₂, or any organicPoly(diazenediacetic acids) and derivatives functional group wherein thenumber of carbon thereof (N—O Tridentates and N—O atoms ranges from 0 to40, optionally having Hexadentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #34:RC(═O)—N═N—C(═O)—R′ for Diazenediformaldehydes, diazenediformaldehydes,and RC(═O)—CR′R′′— Diazenediacetaldehydes, N═N—CR′′′R′′′′—C(═O)—R′′′′′for Bis(diazenediformaldehydes), diazenediacetaldehydes, where R, R′,R′′, R′′′, Bis(diazenediacetaldehydes), R′′′′, and R′′′′′ represent H,NH₂, or any organic Poly(diazenediformaldehydes), and functional groupwherein the number of carbon Poly(diazenediacetaldehydes) (N—O atomsranges from 0 to 40, optionally having Tridentates and N—O Hexadentates)halogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #35: R—N═N—CR′═N—NR′′R′′′, where R, R′, R′′, andOrtho-hydroxy (or -carboxy) Substituted R′′′ represent H, or any organicfunctional Formazans, Bis(o-hydroxy or -carboxy group wherein the numberof carbon atoms substituted formazans), and Poly(o-hydroxy ranges from 0to 40, optionally having halogen or -carboxy substituted formazans) (N—Oor polarizing or water- Bidentates, N—O Tridentates, N—Oinsolubilizing/solubilizing groups attached. Tetradentates, and N—OHexadentates) (Must include ortho-hydroxy or carboxy substituted aryl Rderivatives, and beta-hydroxy or carboxy substituted alkyl Rderivatives.) Ligand can also contain nonbinding N, O, S, or P atoms.N—O Valence Stabilizer #36: RR′C═N—N═CR′′R′′′ or RR′C═N—NR′′R′′′ (forOrtho-hydroxy (or -carboxy) Substituted ketazines), where R, R′, R′′,and R′′′ represent Azines (including ketazines), Bis(o- H, or anyorganic functional group wherein the hydroxy or carboxy substitutedazines), and number of carbon atoms ranges from 0 to 40, Poly(o-hydroxyor carboxy substituted optionally having halogen or polarizing orazines) (N—O Bidentates, N—O Tridentates,water-insolubilizing/solubilizing groups N—O Tetradentates, and N—OHexadentates) attached. (Must include ortho-hydroxy or carboxysubstituted aryl R derivatives, and beta- hydroxy or carboxy substitutedalkyl R derivatives.) Ligand can also contain nonbinding N, O, S, or Patoms. N—O Valence Stabilizer #37: RR′C═N—R′′, where R, R′, and R′′represent H, Schiff Bases with one Imine (C═N) Group or any organicfunctional group wherein the and with ortho- or alpha- or beta-hydroxynumber of carbon atoms ranges from 0 to 40, or carboxy or carbonylsubstitution (N—O optionally having halogen or polarizing or Bidentates,N—O Tridentates, N—O water-insolubilizing/solubilizing groupsTetradentates, N—O Pentadentates, or N—O attached. (Must contain ortho-or alpha- or beta- Hexadentates). Also includes hydrazones hydroxy orcarboxy or carbonyl substitution.) with ortho-O substitution. Ligand canalso contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #38:RR′C═N—R′′—N═CR′′′R′′′′ or R—N═C—R′—C═N—R′ Schiff Bases with two Imine(C═N) Groups or RC═N—R′—N═CR′′, where R, R′, R′′, R′′′, and with ortho-or alpha- or beta-hydroxy and R′′′′ represent H, or any organicfunctional or carboxy or carbonyl substitution (N—O group wherein thenumber of carbon atoms Tridentates, N—O Tetradentates, N—O ranges from 0to 40, optionally having halogen Pentadentates, or N—O Hexadentates).Also or polarizing or water- includes hydrazones with ortho-Oinsolubilizing/solubilizing groups attached. substitution. (Must containortho- or alpha- or beta-hydroxy or carboxy or carbonyl substitution.)Ligand can also contain nonbinding N, O, S, or P atoms. N—O ValenceStabilizer #39: N(—R—N═CR′R′′)₃, where R, R′, and R′′ Schiff Bases withthree Imine (C═N) represent H, or any organic functional group Groupsand with ortho- or alpha- or beta- wherein the number of carbon atomsranges hydroxy or carboxy or carbonyl substitution from 0 to 40,optionally having halogen or (N—O Tetradentates, N—O Pentadentates, orpolarizing or water-insolubilizing/solubilizing N—O Hexadentates). Alsoincludes groups attached. (Must contain ortho- or alpha- hydrazones withortho-O substitution. or beta-hydroxy or carboxy or carbonylsubstitution.) Ligand can also contain nonbinding N, O, S, or P atoms.N—O Valence Stabilizer #40:[R—C(NR′R′′)]_(x)—R′′—[Si(—OR′′′)_(z)R′′′′_(3-z)]_(y) whereSilylaminoalcohols (N—O Bidentates, N—O R, R′, R′′, R′′′, and R′′′′represent H, NH₂, or Tridentates, N—O Tetradentates, and N—O any organicfunctional group wherein the Hexadentates) number of carbon atoms rangesfrom 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached, and x and y = 1-6, z= 1-3. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #41: [R—C(═NR′)]_(x)—R′′—[C(—OR′′′)R′′′′R′′′′′]_(y)or Hydroxyalkyl Imines (Imino Alcohols) (N—O)[R—C(═NR′)]_(x)—R′′—[C(═O)R′′′]_(y) , where R, R′, R′′, Bidentates, N—OTridentates, N—O R′′′, R′′′′, and R′′′′′ represent H, NH₂, or anyTetradentates, and N—O Hexadentates) organic functional group whereinthe number of carbon atoms ranges from 0 to 40, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached, and x and y = 1-6. Ligand can also contain nonbinding N, O, S,or P atoms. N—O Valence Stabilizer #42: [R(—NR′R′′)(—OR′′′)],[R(—NR′R′′)(—C(═O)R′′′], Hydroxyaryl Amines and Hydroxyaryl[R(—NR′R′′)_(x)]₂O, [R(—NR′R′′)_(x)]₂₋₃R′′′(—OR′′′′)_(y), Imines (N—OBidentates, N—O Tridentates, [R(—OR′)_(x)]₂₋₃R′′(—NR′′′R′′′′)_(y), andN—O Tetradentates, and N—O Hexadentates)[R(—NR′R′′)_(x)]₂R′′′(C(═O))_(y)R′′′′ for hydroxyaryl amines; and[R(—OR′)_(x)]₂NH or [R(—OR′)_(x)]₂NHNH for hydroxyaryl imines, where R,R′, R′′, R′′′, and R′′′′ represent H, NH₂, or any organic functionalgroup wherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water-insolubilizing/solubilizing groupsattached, and x = 0-2 and y = 1-4. Ligand can also contain nonbinding N,O, S, or P atoms. N—O Valence Stabilizer #43: Five membered heterocyclicring(s) containing Five-Membered Heterocyclic Rings one, two, three, orfour nitrogen atoms. In containing One, Two, Three, or Four addition,ligand contains additional oxygen- Nitrogen Atoms at least oneadditional containing substituents (usually hydroxy, Oxygen Atom BindingSite not in a Ring carboxy or carbonyl groups) that constitute O (N—OBidentates, N—O Tridentates, N—O binding sites. Can include other ringsystems Tetradentates, or N—O Hexadentates) bound to the heterocyclicring or to the O- containing substituent, but they do not coordinatewith the stabilized, high valence metal ion. Ring(s) can also contain O,S, or P atoms. This 5-membered ring(s) and/or attached, uncoordinatingrings and/or O- containing substituent(s) may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. N—OValence Stabilizer #44: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one, two, three, or four nitrogen atoms.In containing One, Two, Three, or Four addition, ligand containsadditional oxygen- Nitrogen Atoms at least one additional containingsubstituents (usually hydroxy, Oxygen Atom Binding Site not in a Ringcarboxy, or carbonyl groups) that constitute O (N—O Bidentates, N—OTridentates, N—O binding sites. Can include other ring systemsTetradentates, or N—O Hexadentates) bound to the heterocyclic ring or tothe O- containing substituent, but they do not coordinate with thestabilized, high valence metal ion. Ring(s) can also contain O, S, or Patoms. This 6-membered ring(s) and/or attached, uncoordinating ringsand/or O- containing substituent(s) may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. N—OValence Stabilizer #45: Five membered heterocyclic ring(s) containingFive-Membered Heterocyclic Rings one or two oxygen atoms. In addition,ligand containing One or Two Oxygen Atoms at contains additionalnitrogen-containing least one additional Nitrogen Atom Bindingsubstituents (usually amines, imines, or Site not in a Ring (N—OBidentates, N—O hydrazides) that constitute N binding sites. CanTridentates, N—O Tetradentates, or N—O include other ring systems boundto the Hexadentates) heterocyclic ring or to the N-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. This5-membered ring(s) and/or attached, uncoordinating rings and/orN-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N—O ValenceStabilizer #46: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one or two oxygen atoms. In addition,ligand containing One or Two Oxygen Atoms at contains additionalnitrogen-containing least one additional Nitrogen Atom Bindingsubstituents (usually amines, imines, or Site not in a Ring (N—OBidentates, N—O hydrazides) that constitute N binding sites. CanTridentates, N—O Tetradentates, or N—O include other ring systems boundto the Hexadentates) heterocyclic ring or to the N-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. This6-membered ring(s) and/or attached, uncoordinating rings and/orN-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N—O ValenceStabilizer #47: Five membered heterocyclic ring(s) containingFive-Membered Heterocyclic Rings one, two, three, or four nitrogenatoms. In containing One, Two, Three, or Four addition, ligand containsadditional oxygen- Nitrogen Atoms at least one additional containingrings that constitute O binding sites. Oxygen Atom Binding Site in aSeparate Can include other ring systems bound to the N- Ring (N—OBidentates, N—O Tridentates, N—O or O-containing heterocyclic rings, butthey do Tetradentates) not coordinate with the stabilized, high valencemetal ion. Ring(s) can also contain O, S, or P atoms. This 5-memberedring(s) and/or additional O-containing ring(s) and/or attached,uncoordinating rings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. N—O Valence Stabilizer #48:Six membered heterocyclic ring(s) containing Six-Membered HeterocyclicRings one, two, three, or four nitrogen atoms. In containing One, Two,Three, or Four addition, ligand contains additional oxygen- NitrogenAtoms at least one additional containing rings that constitute O bindingsites. Oxygen Atom Binding Site in a Separate Can include other ringsystems bound to the N- Ring (N—O Bidentates, N—O Tridentates, N—O orO-containing heterocyclic rings, but they do Tetradentates) notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, S, or P atoms. This 6-membered ring(s) and/or additionalO-containing ring(s) and/or attached, uncoordinating rings may or maynot have halogen or polarizing or water- insolubilizing/solubilizinggroups attached. N—O Valence Stabilizer #49: Macrocyclic ligandscontaining two, three, four, Two-, Three-, Four-, Six-, Eight-, and Ten-six, eight, or ten binding sites composed of Membered Macrocyclics,Macrobicyclics, nitrogen and oxygen to valence stabilize the andMacropolycyclics (including central metal ion. Can include otherCatapinands, Cryptands, Cyclidenes, and hydrocarbon or ring systemsbound to this Sepulchrates) wherein all Binding Sites are macrocyclicligand, but they do not coordinate composed of Nitrogen (usually amineor with the stabilized, high valence metal ion. This imine groups) orOxygen (usually hydroxy, ligand and/or attached, uncoordinating carboxy,or carbonyl groups) and are not hydrocarbons/rings may or may not havecontained in Component Heterocyclic halogen or polarizing or water-Rings (N—O Bidentates, N—O Tridentates, insolubilizing/solubilizinggroups attached. N—O Tetradentates, and N—O Hexadentates) N—O ValenceStabilizer #50: Macrocyclic ligands containing a total of four, Four-,Six-, Eight-, or Ten-Membered six, eight, or ten heterocyclic ringscontaining Macrocyclics, Macrobicyclics, and nitrogen or oxygen bindingsites. Can include Macropolycyclics (including Catapinands, otherhydrocarbon/ring systems bound to this Cryptands, Cyclidenes, andSepulchrates) macrocyclic ligand, but they do not coordinate wherein allBinding Sites are composed of with the stabilized, high valence metalion. This Nitrogen or Oxygen and are contained in ligand and/orattached, uncoordinating Component Heterocyclic Rings (N—Ohydrocarbon/rings may or may not have halogen Bidentates, N—OTridentates, N—O or polarizing or water-insolubilizing groupsTetradentates, or N—O Hexadentates) attached. N—O Valence Stabilizer#51: Macrocyclic ligands containing at least one Four-, Six-, Eight-, orTen-Membered heterocyclic ring. These heterocyclic rings Macrocyclics,Macrobicyclics, and provide nitrogen or oxygen binding sites toMacropolycyclics (including Catapinands, valence stabilize the centralmetal ion. Other Cryptands, Cyclidenes, and Sepulchrates) amine, imine,hydroxy, carboxy, or carbonyl wherein all Binding Sites are composed ofbinding sites can also be included in the Nitrogen or Oxygen and arecontained in a macrocyclic ligand, so long as the total numberCombination of Heterocyclic Rings and of binding sites is four, six,eight, or ten. Can Amine, Imine, Hydroxy, Carboxy, or include otherhydrocarbon/ring systems bound Carbonyl Groups (N—O Bidentates, N—O tothis macrocyclic ligand, but they do not Tridentates, N—O Tetradentates,or N—O coordinate with the stabilized, high valence Hexadentates) metalion. This ligand and/or attached, uncoordinating hydrocarbon/rings mayor may not have halogen or polarizing or water- insolubilizing groupsattached. S—O Valence Stabilizer #1: R—C(═S)—CR′R′′—C(═O)—R′′′ where R,R′, R′′, 1,3-Monothioketones (Monothio-beta- and R′′′ represent H, NH₂,or any organic ketonates), 1,3,5-Monothioketones, 1,3,5- functionalgroup wherein the number of carbon Dithioketones,Bis(1,3-Monothioketones), atoms ranges from 0 to 40, optionally havingand Poly(1,3-Monothioketones) (S—O halogen or polarizing or water-Bidentates, S—O Tridentates, S—O insolubilizing/solubilizing groupsattached. Tetradentates) Ligand can also contain nonbinding N, O, S, orP atoms. S—O Valence Stabilizer #2:RR′—N—C(═S)—CR′′R′′′—C(═O)—N—R′′′′R′′′′′ Thiomalonamides(Thiomalonodiamides), where R, R′, R′′, R′′′, R′′′′, and R′′′′′represent H, Bis(thiomalonamides), and NH₂, or any organic functionalgroup wherein Polythiomalonamides (S—O Bidentates, S—O the number ofcarbon atoms ranges from 0 to Tridentates, S—O Tetradentates) 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #3:RR′—N—C(═O)—CR′′R′′′—C(═S)—R′′′′ for 2- 2-Thioacylacetamides,thioacylacetamides, and RR′—N—C(═S)—CR′′R′′′— 2-Acylthioacetamides,C(═O)—R′′′′ for 2-acylthioacetamides, where R,Bis(2-thioacylacetamides), R′, R′′, R′′′, and R′′′′ represent H, NH₂, orany Bis(2acylthioacetamides), Poly(2- organic functional group whereinthe number of thioacylacetamides), and Poly(2- carbon atoms ranges from0 to 40, optionally Acylthioacetamides) (S—O Bidentates, S—O havinghalogen or polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #4:RR′—N—C(═S)—S—C(═O)—N—R′′R′′′ where R, R′, Dithiodicarbonic Diamides,R′′, and R′′′ represent H, NH₂ or any organic Bis(dithiodicarbonicdiamides), and functional group wherein the number of carbonPoly(dithiodicarbonic diamides) (S—O atoms ranges from 0 to 40,optionally having Bidentates, S—O Tridentates, S—O halogen or polarizingor water- Tetradentates) insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. S—O ValenceStabilizer #5: (R—O—)(R′—O—)P(═S)—P(═O)(—O—R′′)(—O—R′′′);Monothiohypophosphoric Acids, (R—O—)(R′—S—)P(═S)—P(═O)(—S—R′′)(—O—R′′′);or Bis(monothiohypophosphoric acids), and(R—S—)(R′—S—)P(═S)—P(═O)(—S—R′′)(—S—R′′′), Poly(monothiohypophosphoricacids), and where R, R′, R′′, and R′′′ represent H, NH₂ or derivativesthereof (S—O Bidentates, S—O any organic functional group wherein theTridentates, S—O Tetradentates) number of carbon atoms ranges from 0 to40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. Note: these ligands are not tobe confused with hypophosphorous acid derivatives (hypophosphites)(R—O—)R′′R′′′P(═O) which are very reducing and therefore unacceptablefor stabilization of high valence states in metal ions. S—O ValenceStabilizer #6: (RR′—N—)(R′′R′′′—N—)P(═S)—P(═O)(—N—Monothiohypophosphoramides, R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′), where R,R′, R′′, R′′′, Bis(monothiohypophosphoramides), and R′′′′, R′′′′′,R′′′′′′, and R′′′′′′′ represent H, NH₂ orPoly(monothiohypophosphoramides) (S—O any organic functional groupwherein the Bidentates, S—O Tridentates, S—O number of carbon atomsranges from 0 to 40, Tetradentates) optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. Note: these ligands arenot to be confused with hypophosphorous acid derivatives(hypophosphites) (R—O—)R′′R′′′P(═O) which are very reducing andtherefore unacceptable for stabilization of high valence states in metalions. S—O Valence Stabilizer #7:(R—O—)(R′—O—)P(═S)—NH—P(═O)(—O—R′′)(—O—R′′′); MonothioimidodiphosphoricAcids, (R—O—)(R′—S—)P(═S)—NH—P(═O)(—S—R′′)(—O—R′′′);Monothiohydrazidodiphosphoric Acids, or(R—S—)(R′—S—)P(═S)—NH—P(═O)(—S—R′′)(—S—R′′′)Bis(monothioimidodiphosphoric Acids), for monothioimidodiphosphoricBis(monothiohydrazidodiphosphoric acids, and —NH—NH— derivatives forAcids), Poly(monothioimidodiphosphoric monothiohydrazidodiphosphoricacids, where Acid), Poly(monothiohydrazidodiphosphoric R, R′, R′′, andR′′′ represent H, NH₂ or any Acids), and derivatives thereof (S—Oorganic functional group wherein the number of Bidentates, S—OTridentates, S—O carbon atoms ranges from 0 to 40, optionallyTetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #8:(RR′—N—)(R′′R′′′—N—)P(═S)—NH—P(═O)(—N— Monothioimidodiphosphoramides,R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′) for Monothiohydrazidodiphosphoramides,monothioimidodiphosphoramides, and —NH—NH—Bis(monothioimidodiphosphoramides), derivatives formonothiohydrazidodiphosphoramides,Bis(monothiohydrazidodiphosphoramides), where R, R′, R′′, R′′′, R′′′′,R′′′′′, R′′′′′′, and R′′′′′′′ Poly(monothioimidodiphosphoramides),represent H, NH₂ or any organic functional and group wherein the numberof carbon atoms ranges from Poly(monothiohydrazidodiphosphoramides) 0 to40, optionally having halogen or polarizing or water- (S—O Bidentates,S—O Tridentates, S—O insolubilizing/solubilizing groups attached.Tetradentates) Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #9: (RR′—N—)(R′′R′′′—N—)P(═S)—S—P(═O)(—N—Monothiodiphosphoramides, R′′′′R′′′′′)(—N—R′′′′′′R′′′′′′′), or(RR′—N—)(R′′R′′′— Bis(monothioiphosphoramides), andN—)P(═S)—O—P(═O)(—N—R′′′′R′′′′′)(—N— Poly(monothiodiphosphoramides) (S—OR′′′′′′R′′′′′′′), where R, R′, R′′, R′′′, R′′′′, R′′′′′, Bidentates, S—OTridentates, S—O R′′′′′′, and R′′′′′′′ represent H, NH₂ or anyTetradentates) organic functional group wherein the number of carbonatoms ranges from 0 to 40, optionally having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #10:(R—O—)(R′—O—)P(═S)—O—P(═O)(—O—R′′)(—O—R′′′); Monothiodiphosphoric Acids,(R—O—)(R′—O—)P(═S)—S—P(═O)(—O—R′′)(—O—R′′′); Bis(monothioiphosphoricAcids), (R—O—)(R′—S—)P(═S)—O—P(═O)(—S—R′′)(—O—R′′′);Poly(monothiodiphosphoric Acids), and(R—O—)(R′—S—)P(═S)—S—P(═O)(—S—R′′)(—O—R′′′); derivatives thereof (S—OBidentates, S—O or (R—S—)(R′—S—)P(═S)—S—P(═O)(—S—R′′)(—S—R′′′),Tridentates, S—O Tetradentates) where R, R′, R′′, R′′′, R′′′′, R′′′′′,R′′′′′′, and R′′′′′′′ represent H, NH₂ or any organic functional groupwherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #11: RR′N⁺═C(OH)(SH), where R and R′ representMonothiocarbamates, H, OH, SH, OR′′ (R′′ = C₁-C₃₀ alkyl or aryl), SR′′Bis(monothiocarbamates), and (R′′ = C₁-C₃₀ alkyl or aryl), NH₂ or anyorganic Poly(monothiocarbamates) (including N- functional group whereinthe number of carbon hydroxymonothiocarbamates and N- atoms ranges from0 to 40, optionally having mercaptomonothiocarbamates) (S—O halogen orpolarizing or water- Bidentates, S—O Tridentates, and S—Oinsolubilizing/solubilizing groups attached. Tetradentates) Ligand canalso contain nonbinding N, O, S, or P atoms.

N Valence Stabilizer #1: Examples of monoamines (N monodentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: ammonia, ethylamine,n-dodecylamine, octylamine, phenylamine, cyclohexylamine, diethylamine,dioctylamine, diphenylamine, dicyclohexylamine, azetidine,hexamethylenetetramine, aziridine, azepine, pyrrolidine,benzopyrrolidine, dibenzopyrrolidine, naphthopyrrolidine, piperidine,benzopiperidine, dibenzopiperidine, naphthopiperidine, azacycloheptane(hexamethyleneimine (Urotropin)), aminonorbornane, adamantanamine,aniline, benzylamine, toluidine, phenethylamine, xylidine, cumidine,naphthylamine, polyalkylamines, polyanilines, and fluorenediamine.

N Valence Stabilizer #2: Examples of diamines (N—N bidentates) that meetthe requirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: hydrazine, phenylhydrazine,1,1-diphenylhydrazine, 1,2-diphenylhydrazine (hydrazobenzene),methanediamine, ethylenediamine (1,2-ethanediamine, en),trimethylenediamine (1,3-propanediamine), putrescine(1,4-butanediamine), cadaverine (1,5-pentanediamine),hexamethylenediamine (1,6-hexanediamine), 2,3-diaminobutane,stilbenediamine (1,2-diphenyl-1,2-ethanediamine),cyclohexane-1,2-diamine, cyclopentane-1,2-diamine,1,3-diazacyclopentane, 1,3-diazacyclohexane, piperazine,benzopiperazine, dibenzopiperazine, naphthopiperazine, diazepine,thiadiazepine, oxodiazepine, sparteine (lupinidine),2-(aminomethyl)azacyclohexane, 2-(aminomethyl)piperidine,2-(aminomethyl)pyrrolidine, 2-(aminomethyl)azetidine,2-(2-aminoethyl)aziridine, 1,2-diaminobenzene, benzidine,bis(2,2′-piperazino)-1,2-ethene, 1,4-diazabicyclo[2.2.2]octane,naphthylethylenediamine, and 1,2-dianilinoethane.

N Valence Stabilizer #3: Examples of triamines (N—N bidentates or N—Ntridentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:N-(2-aminoethyl)-1,2-ethanediamine (dien, 2,2-tri);N-(2-aminoethyl)-1,3-propanediamine (2,3-tri);N-(3aminopropyl)-1,3-propanediamine (3,3-tri, dpt);N-(3-aminopropyl)-1,4-butanediamine (3,4-tri, spermidine);N-(2-aminoethyl)-1,4-butanediamine (2,4-tri);N-(6-hexyl)-1,6-hexanediamine (6,6-tri); 1,3,5-triaminocyclohexane(tach); 2-(aminomethyl)-1,3-propanediamine (tamm);2-(aminomethyl)-2-methyl-1,3-propanediamine (tame);2-(aminomethyl)-2-ethyl-1,3-propanediamine (tamp); 1,2,3-triaminopropane(tap); 2,3-(2-aminoethyl)aziridine; 2,4-(aminomethyl)azetidine;2,5-(aminomethyl)pyrrolidine; 2,6,-(aminomethyl)piperidine;di(2-aminobenzyl)amine; hexahydro-1,3,5-triazine;hexahydro-2,4,6-trimethyl-1,3,5-triazine; and1,3,5-tris(aminomethyl)benzene.

N Valence Stabilizer #4: Examples of tetramines (N—N bidentates, N—Ntridentates, or N—N tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N,N′-(2-aminoethyl)-1,2-ethanediamine (2,2,2-tet, trien(triethylenetetramine)); N,N′-(2-aminoethyl)-1,3-propanediamine(2,3,2-tet, entnen); N,N′-(3-aminopropyl)-1,2-ethanediamine (3,2,3-tet,tnentn); N-(2-aminoethyl)-N′-(3-aminopropyl)-1,2-ethanediamine(2,2,3-tet); N-(2-aminoethyl)-N′-(3-aminopropyl)-1,3-propanediamine(3,3,2-tet); N,N′-(3-aminopropyl)-1,3-propanediamine (3,3,3-tet);N,N′-(3-aminopropyl)-1,4-butanediamine (3,4,3-tet, spermine);tri(aminomethyl)amine (tren); tri(2-aminoethyl)amine (trtn);tri(3-aminopropyl)amine (trbn); 2,2-aminomethyl-1,3-propanediamine(tam); 1,2,3,4-tetraaminobutane (tab);N,N′-(2-aminophenyl)-1,2-ethanediamine; andN,N′-(2-aminophenyl)-1,3-propanediamine.

N Valence Stabilizer #5: Examples of pentamines (N—N bidentates, N—Ntridentates, or N—N tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto:N-[N-(2-aminoethyl)-2-aminoethyl]-N′-(2-aminoethyl)-1,2-ethanediamine(2,2,2,2-pent, tetren);N-[N-(3-aminopropyl)-2-aminoethyl]-N′-(3-aminopropyl)-1,2-ethanediamine(3,2,2,3-pent);N-[N-(3-aminopropyl)-3-aminopropyl]-N′-(3-aminopropyl)-1,3-propanediamine(3,3,3,3-pent, caldopentamine);N-[N-(2-aminobenzyl)-2-aminoethyl]-N′-(2-aminopropyl)-1,2-ethanediamine;N-[N-(2-aminoethyl)-2-aminoethyl]-N,N-(2-aminoethyl)amine (trenen); andN-[N-(2-aminopropyl)-2-aminoethyl]-N,N-(2-aminoethyl)amine(4-Me-trenen).

N Valence Stabilizer #6: Examples of hexamines (N—N bidentates, N—Ntridentates, N—N tetradentates, or N—N—N—N—N—N hexadentates) that meetthe requirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to:N,N′-[N-(2-aminoethyl)-2-aminoethyl]-1,2-ethanediamine (2,2,2,2,2-hex,linpen); N,N′-[N-(2-aminoethyl)-3-aminopropyl]-1,2-ethanediamine(2,3,2,3,2-hex); N,N,N′,N′-(2-aminoethyl)-1,2-ethanediamine (penten,ten); N,N,N′,N′-(2-aminoethyl)-1-methyl-1,2-ethanediamine (tpn,R-5-Me-penten); N,N,N′,N′-(2-aminoethyl)-1,3-propanediamine (ttn);N,N,N′,N′-(2-aminoethyl)-1,4-butanediamine (tbn);N,N,N′,N′-(2-aminoethyl)-1,3-dimethyl-1,3-propanediamine (R,R-tptn,R,S-tptn);N-(2-aminoethyl)-2,2-[N-(2-aminoethyl)aminomethyl-1-propaneamine (sen);and N-(3-aminopropyl)-2,2-[N-(3-aminopropyl)aminomethyl-1-propaneamine(stn).

N Valence Stabilizer #7a: Examples of 5-membered heterocyclic ringscontaining one nitrogen atom (N monodentates) that meet the requirementsfor use as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 1-pyrroline, 2-pyrroline, 3-pyrroline, pyrrole, oxazole,isoxazole, thiazole, isothiazole, azaphosphole, benzopyrroline,benzopyrrole (indole), benzoxazole, benzisoxazole, benzothiazole,benzisothiazole, benzazaphosphole, dibenzopyrroline, dibenzopyrrole(carbazole), dibenzoxazole, dibenzisoxazole, dibenzothiazole,dibenzisothiazole, naphthopyrroline, naphthopyrrole, naphthoxazole,naphthisoxazole, naphthothiazole, naphthisothiazole, naphthazaphosphole,and polypyrroles.

N Valence Stabilizer #7b: Examples of 5-membered heterocyclic ringscontaining two nitrogen atoms (N monodentates or N—N bidentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: pyrazoline, imidazoline, imidazole(ia), pyrazole, oxadiazole, thiadiazole, diazaphosphole,benzopyrazoline, benzimidazoline, benzimidazole (azindole)(bia)(bz),benzopyrazole (indazole), benzothiadiazole (piazthiole), benzoxadiazole(benzofurazan), naphthopyrazoline, naphthimidazoline, naphthimidazole,naphthopyrazole, naphthoxadiazole, naphthothiadiazole,polybenzimidazole, and polyimidazoles (e.g. polyvinylimidazole (pvi)).

N Valence Stabilizer #7c: Examples of 5-membered heterocyclic ringscontaining three nitrogen atoms (N monodentates, N—N bidentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: triazole, oxatriazole,thiatriazole, benzotriazole (bta), tolyltriazole (tt), naphthotriazole,and triazolophthalazine.

N Valence Stabilizer #7d: Examples of 5-membered heterocyclic ringscontaining four nitrogen atoms (N monodentates or N—N bidentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: tetrazole.

N Valence Stabilizer #8a: Examples of 6-membered heterocyclic ringscontaining one nitrogen atom (N monodentates) that meet the requirementsfor use as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: pyridine, picoline, lutidine, -collidine, oxazine, thiazine,azaphosphorin, quinoline, isoquinoline, benzoxazine, benzothiazine,benzazaphosphorin, acridine, phenanthridine, phenothiazine(dibenzothiazine), dibenzoxazine, dibenzazaphosphorin, benzoquinoline(naphthopyridine), naphthoxazine, naphthothiazine, naphthazaphosphorin,and polypyridines.

N Valence Stabilizer #8b: Examples of 6-membered heterocyclic ringscontaining two nitrogen atoms (N monodentates or N—N bidentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: pyrazine, pyridazine, pyrimidine,oxadiazine, thiadiazine, diazaphosphorin, quinoxaline (benzopyrazine),cinnoline (benzo[c]pyridazine), quinazoline (benzopyrimidine),phthalazine (benzo[d]pyridazine), benzoxadiazine, benzothiadiazine,phenazine (dibenzopyrazine), dibenzopyridazine, naphthopyrazine,naphthopyridazine, naphthopyrimidine, naphthoxadiazine,naphthothiadiazine, and polyquinoxalines.

N Valence Stabilizer #8c: Examples of 6-membered heterocyclic ringscontaining three nitrogen atoms (N monodentates or N—N bidentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: 1,3,5-triazine, 1,2,3-triazine,benzo-1,2,3-triazine, naphtho-1,2,3-triazine, oxatriazine, thiatriazine,melamine, and cyanuric acid.

N Valence Stabilizer #8d: Examples of 6-membered heterocyclic ringscontaining four nitrogen atoms (N monodentates or N—N bidentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: tetrazine.

N Valence Stabilizer #9a: Examples of 5-membered heterocyclic ringscontaining one nitrogen atom and having at least one additional nitrogenatom binding site not contained in a ring (N Monodentates, N—NBidentates, N—N Tridentates, N—N Tetradentates, or N—N Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-(aminomethyl)3-pyrroline;2,5-(aminomethyl)3-pyrroline; 2-(aminomethyl)pyrrole;2,5-(aminomethyl)pyrrole; 3-(aminomethyl)isoxazole;2-(aminomethyl)thiazole; 3-(aminomethyl)isothiazole;2-(aminomethyl)indole; 2-aminobenzoxazole; 2-aminobenzothiazole (abt);1,8-diaminocarbazole; 2-amino-6-methyl-benzothiazole (amebt);2-amino-6-methoxybenzothiazole (ameobt); and 1,3-diiminoisoindoline.

N Valence Stabilizer #9b: Examples of 5-membered heterocyclic ringscontaining two nitrogen atoms at least one additional nitrogen atombinding site not contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-aminoimidazoline;1-(3-aminopropyl)imidazoline; 2-aminoimidazole;1-(3-aminopropyl)imidazole; 4-(2-aminoethyl)imidazole [histamine];1-alkyl-4-(2-aminoethyl)imidazole; 3-(2-aminoethyl)pyrazole;3,5-(2-aminoethyl)pyrazole; 1-(aminomethyl)pyrazole;2-aminobenzimidazole; 7-(2-aminoethyl)benzimidazole;1-(3-aminopropyl)benzimidazole; 3-(2-aminoethyl)indazole;3,7-(2-aminoethyl)indazole; 1-(aminomethyl)indazole;7-aminobenzothiadiazole; 4-(2-aminoethyl)benzothiadiazole;7-aminobenzoxadiazole; 4-(2-aminoethyl)benzoxadiazole;ethylenediaminetetra(1-pyrazolylmethane) [edtp];methylenenitrilotris(2-(1-methyl)benzimidazole) [mntb];[tris(1-methyl-2-benzimidazolylmethane)amine];bis(alkyl-1-pyrazolylmethane)amine;bis(alkyl-2-(1-pyrazolyl)ethane)amine;bis(N,N-(2-benzimidazolyl)-2-aminoethane)(2-benzimidazolylmethane)amine;bis(1-(3,5-dimethyl)pyrazolylmethane)phenylamine;tris(2-(1-(3,5-dimethyl)pyrazolyl)ethane)amine;5-(dimethylamino)pyrazole; 5-(dimethylaminomethyl)pyrazole;2-amino-1,3,4-thiadiazole; and 1-(2-aminoethyl)imidazoline.

N Valence Stabilizer #9c: Examples of 5-membered heterocyclic ringscontaining three nitrogen atoms at least one additional nitrogen atombinding site not contained in a ring (N Monodentates, N—N Bidentates,N—N—N Tridentates, N—N—N—N Tetradentates, or N—N—N—N—N—N Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 3-amino-1,2,4-triazole (ata);3,5-diamino-1,2,4-triazole (dat); 5-amino-1,2,4-triazole;3-(2-aminoethyl) 1,2,4-triazole; 5-(2-aminoethyl)-1,2,4-triazole;3,5-(2-aminoethyl 1,2,4-triazole; 1-(aminomethyl) 1,2,4-triazole;3,5-(aminomethyl)-4-amino-1,2,4-triazole;4-(2-aminoethyl)-1,2,3-triazole; 5-(2-aminoethyl)-1,2,3-triazole;7-aminobenzotriazole; 1-(aminomethyl)-1,2,3-triazole;1-(2-aminoethyl)-1,2,3-triazole; 4-(3-aminopropyl)benzotriazole;N-(benzotriazolylalkyl)amine; dibenzotriazole-1-ylalkylamine;bis(5-amino-1,2,4-triazol-3-yl); bis(5-amino-1,2,4-triazol-3-yl)alkanes;and 1-(aminomethyl)benzotriazole.

N Valence Stabilizer #9d: Examples of 5-membered heterocyclic ringscontaining four nitrogen atoms at least one additional nitrogen atombinding site not contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 5-(2-aminoethyl)-1H-tetrazole;1-(aminomethyl)-1H-tetrazole; and 1-(2-aminoethyl)-1H-tetrazole.

N Valence Stabilizer #10a: Examples of 6-membered heterocyclic ringscontaining one nitrogen atom and having at least one additional nitrogenatom binding site not contained in a ring (N Monodentates, N—NBidentates, N—N Tridentates, N—N Tetradentates, or N—N Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-aminopyridine;2,6-diaminopyridine; 2-(aminomethyl)pyridine; 2,6-(aminomethyl)pyridine;2,6-(aminoethyl)pyridine; 2-amino-4-picoline; 2,6-diamino-4-picoline;2-amino-3,5-lutidine; 2-aminoquinoline; 8-aminoquinoline;2-aminoisoquinoline; acriflavine; 4-aminophenanthridine;4,5-(aminomethyl)phenothiazine; 4,5-(aminomethyl)dibenzoxazine;10-amino-7,8-benzoquinoline; bis(2-pyridylmethane)amine;tris(2-pyridyl)amine; bis(4(2-pyridyl)-3-azabutane)amine;bis(N,N-(2-(2-pyridyl)ethane)aminomethane)amine;4-(N,N-dialkylaminomethyl)morpholine; 6-aminonicotinic acid;8-aminoacridine; and 2-hydrazinopyridine.

N Valence Stabilizer #10b: Examples of 6-membered heterocyclic ringscontaining two nitrogen atoms at least one additional nitrogen atombinding site not contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-aminopyrazine; 2,6-diaminopyrazine;2-(aminomethyl)pyrazine; 2,6-(aminomethyl)pyrazine;3-(aminomethyl)pyridazine; 3,6(aminomethyl)pyridazine;3,6-(2-aminoethyl)pyridazine; 1-aminopyridazine;1-(aminomethyl)pyridazine; 2-aminopyrimidine;1-(2-aminoethyl)pyrimidine; 2-aminoquinoxaline; 2,3-diaminoquinoxaline;2-aminocinnoline; 3-aminocinnoline; 3-(2-aminoethyl)cinnoline;3,8-(2-aminoethyl)cinnoline; 2-aminoquinazoline;1-(2-aminoethyl)quinazoline; 1-aminophthalazine;1,4-(2-aminoethyl)phthalazine; 1,8-(aminomethyl)phenazine;2-amino-4,6-dimethylpyrimidine (admp); dihydralazine; and hydralazine.

N Valence Stabilizer #10c: Examples of 6-membered heterocyclic ringscontaining three nitrogen atoms at least one additional nitrogen atombinding site not contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-amino-1,3,5-triazine;2-(aminomethyl)-1,3,5-triazine; 2,6-(aminomethyl)-1,3,5-triazine;1-(3-aminopropyl)-1,3,5-triazine; 1,5-(3-aminopropyl)-I,3,5-triazine;polymelamines; melamine; and altretamine.

N Valence Stabilizer #10d: Examples of 6-membered heterocyclic ringscontaining four nitrogen atoms at least one additional nitrogen atombinding site not contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 3,6-(2-aminoethyl)-1,2,4,5-tetrazine;3,6-(1,3-diamino-2-propyl)-1,2,4,5-tetrazine; and4,6-(aminomethyl)-1,2,3,5-tetrazine.

N Valence Stabilizer #11a: Examples of 5-membered heterocyclic ringscontaining one nitrogen atom and having at least one additional nitrogenatom binding site contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2,2′-bi-3-pyrroline; 2,2′-bi-2-pyrroline; 2,2′-bi-1-pyrroline;2,2′-bipyrrole; 2,2′,2″-tripyrrole; 3,3′-biisoxazole; 2,2′-bioxazole;3,3′-biisothiazole; 2,2′-bithiazole; 2,2′-biindole; 2,2′-bibenzoxazole;2,2′-bibenzothiazole; bilirubin; biliverdine; and 7-azaindole.

N Valence Stabilizer #11b: Examples of 5-membered heterocyclic ringscontaining two nitrogen atoms at least one additional nitrogen atombinding site contained in a ring (N Monodentates, N—N Bidentates, N—NTridentates, N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2,2′-bi-2-imidazoline [2,2′-bi-2-imidazolinyl] [bimd];2,2′-biimidazole [2,2′-biimidazolyl] [biimH₂]; 5,5′-bipyrazole;3,3′-bipyrazole; 4,4′-bipyrazole [4,4′-bipyrazolyl] [bpz];2,2′-bioxadiazole; 2,2′-bithiadiazole; 2,2′-bibenzimidazole;7,7′-biindazole; 5,5′-bibenzofurazan; 5,5′-bibenzothiadiazole;bis-1,2-(2-benzimidazole)ethane; bis(2-benzimidazole)methane;1,2-(2-imidazolyl)benzene; 2-(2-thiazolyl)benzimidazole;2-(2-imidazolyl)benzimidazole; benzimidazotriazine; 4-azabenzimidazole;and 2,6-bis(2-benzimidazolyl)pyridine.

N Valence Stabilizer #11c: Examples of 5-membered heterocyclic ringscontaining three nitrogen atoms at least one additional nitrogen atombinding site contained in a ring (N Monodentates, N—N Bidentates, N—NTridentates, N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 5,5′-bi-1,2,4-triazole [btrz]; 3,3′-bi-1,2,4-triazole;1,1′-bi-1,2,4-triazole; 1,1′-bi-1,2,3-triazole; 5,5′-bi-1,2,3-triazole;7,7′-bibenzotriazole; 1,1′-bibenzotriazole; bis(pyridyl)aminotriazole(pat); and 8-azaadenine.

N Valence Stabilizer #11d: Examples of 5-membered heterocyclic ringscontaining four nitrogen atoms at least one additional nitrogen atombinding site contained in a ring (N Monodentates, N—N Bidentates, N—NTridentates, N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 5,5′-bi-1H-tetrazole; and 1,1′-bi-1H-tetrazole.

N Valence Stabilizer #12a: Examples of 6-membered heterocyclic ringscontaining one nitrogen atom and having at least one additional nitrogenatom binding site contained in a ring (N Monodentates, N—N Bidentates,N—N Tridentates, N—N Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2,2′-bipyridine [bipy]; 2,2′,2″-tripyridine [terpyridine] [terpy];2,2′,2″,2′″-tetrapyridine [tetrapy]; 6,6′-bi-2-picoline;6,6′-bi-3-picoline; 6,6′-bi-4-picoline; 6,6′-bi-2,3-lutidine;6,6′-bi-2,4-lutidine; 6,6′-bi-3,4-lutidine; 6,6′-bi-2,3,4-collidine;2,2′-biquinoline; 2,2′-biisoquinoline; 3,3′-bibenzoxazine;3,3′-bibenzothiazine; 1,10-phenanthroline [phen]; 1,8-naphthyridine;bis-1,2-(6-(2,2′-bipyridyl))ethane; bis-1,3-(6-(2,2′-bipyridyl))propane;3,5-bis(3-pyridyl)pyrazole; 3,5-bis(2-pyridyl)triazole;1,3-bis(2-pyridyl)-1,3,5-triazine;1,3-bis(2-pyridyl)-5-(3-pyridyl)-1,3,5-triazine;2,7-(N,N′-di-2-pyridyl)diaminobenzopyrroline;2,7-(N,N′-di-2-pyridyl)diaminophthalazine;2,6-di-(2-benzothiazolyl)pyridine; triazolopyrimidine;2-(2-pyridyl)imidazoline; 7-azaindole; 1-(2-pyridyl)pyrazole;(1-imidazolyl)(2-pyridyl)methane;4,5-bis(N,N′-(2-(2-pyridyl)ethyl)iminomethyl)imidazole;bathophenanthroline; 4(2-benzimidazolyl)quinoline;1,2-bis(2-pyridyl)ethane; 4,4′-diphenyl-2,2′-dipyridyl; neocuproine;nicotine; and nornicotine.

N Valence Stabilizer #12b: Examples of 6-membered heterocyclic ringscontaining two nitrogen atoms at least one additional nitrogen atombinding site contained in a ring (N Monodentates, N—N Bidentates, N—NTridentates, N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2,2′-bipyrazine; 2,2′,2″-tripyrazine; 6,6′-bipyridazine;bis(3-pyridazinyl)methane; 1,2-bis(3-pyridazinyl)ethane;2,2′-bipyrimidine; 2,2′-biquinoxaline; 8,8′-biquinoxaline;bis(3-cinnolinyl)methane; bis(3-cinnolinyl)ethane; 8,8′-bicinnoline;2,2′-biquinazoline; 4,4′-biquinazoline; 8,8′-biquinazoline;2,2′-biphthalazine; 1,1′-biphthalazine; 2-(2-pyridyl)benzimidazole;8-azapurine; purine; adenine; guanine; hypoxanthine;2,6-bis(N,N′-(2-(4-imidazolyl)ethyl)iminomethyl)pyridine;2-(N-(2-(4-imidazolyl)ethyl)iminomethyl)pyridine; adenine (aminopurine);purine; and 2,3-bis(2-pyridyl)pyrazine.

N Valence Stabilizer #12c: Examples of 6-membered heterocyclic ringscontaining three nitrogen atoms at least one additional nitrogen atombinding site contained in a ring (N Monodentates, N—N Bidentates, N—NTridentates, N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2,2′-bi-1,3,5-triazine; 2,2′,2″-tri-1,3,5-triazine;4,4′-bi-1,2,3-triazine; and 4,4′-bibenzo-1,2,3-triazine;2,4,6-tris(2-pyridyl 1,3,5-triazine; and benzimidazotriazines.

N Valence Stabilizer #12d: Examples of 6-membered heterocyclic ringscontaining four nitrogen atoms at least one additional nitrogen atombinding site contained in a ring (N Monodentates, N—N Bidentates, N—NTridentates, N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 3,3′-bi-1,2,4,5-tetrazine; and 4,4′-bi-1,2,3,5-tetrazine.

N Valence Stabilizer #13a: Examples of two-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein both binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Bidentates) that meet the requirementsfor use as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazacyclobutane ([4]aneN₂); diazacyclopentane ([5]aneN₂);diazacyclohexane ([6]aneN₂); diazacycloheptane ([7]aneN₂);diazacyclooctane ([8]aneN₂); piperazine; benzopiperazine;diazacyclobutene ([4]eneN₂); diazacyclopentene ([5]eneN₂);diazacyclohexene ([6]eneN₂); diazacycloheptene ([7]eneN₂);diazacyclooctene ([8]eneN₂); diazacyclobutadiene ([4]dieneN₂);diazacyclopentadiene ([5]dieneN₂); diazacyclohexadiene ([6]dieneN₂);diazacycloheptadiene ([7]dieneN₂); and diazacyclooctadiene ([8]dieneN₂).

N Valence Stabilizer #13b: Examples of three-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: triazacyclohexane (includinghexahydro-1,3,5-triazine)([6]aneN₃); triazacycloheptane ([7]aneN₃);triazacyclooctane ([8]aneN₃); triazacyclononane ([9]aneN₃);triazacyclodecane ([10]aneN₃); triazacycloundecane ([11]aneN₃);triazacyclododecane ([12]aneN₃); triazacyclohexene ([6]eneN₃);triazacycloheptene ([7]eneN₃); triazacyclooctene ([8]eneN₃);triazacyclononene ([9]eneN₃); triazacyclodecene ([10]eneN₃);triazacycloundecene ([11]eneN₃); triazacyclododecene ([12]eneN₃);triazacyclohexatriene ([6]trieneN₃); triazacycloheptatriene([7]trieneN₃); triazacyclooctatriene ([8]trieneN₃);triazacyclononatriene ([9]trieneN₃); triazacyclodecatriene([10]trieneN₃); triazacycloundecatriene ([11])trieneN₃); andtriazacyclododecatriene ([12]trieneN₃).

N Valence Stabilizer #13c: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetraazacyclooctane ([8]aneN₄);tetraazacyclononane ([9]aneN₄); tetraazacyclodecane ([10]aneN₄);tetraazacycloundecane ([11]aneN₄); tetraazacyclododecane ([12]aneN₄);tetraazacyclotridecane ([13]aneN₄) tetraazacyclotetradecane ([14]aneN₄);tetraazacyclopentadecane ([15]aneN₄); tetraazacyclohexadecane([16]aneN₄); tetraazacycloheptadecane ([17]aneN₄);tetraazacyclooctadecane ([18]aneN₄); tetraazacyclononadecane([19]aneN₄); tetraazacycloeicosane ([20]aneN₄); tetraazacyclooctadiene([8]dieneN₄); tetraazacyclononadiene ([9]dieneN₄);tetraazacyclodecadiene ([10]dieneN₄); tetraazacycloundecadiene([11]diene tetraazacyclododecadiene ([12]dieneN₄);tetraazacyclotridecadiene ([13]dieneN₄); tetraazacyclotetradecadiene([14]dieneN₄); tetraazacyclopentadecadiene ([15]dieneN₄);tetraazacyclohexadecadiene ([16]dieneN₄); tetraazacycloheptadecadiene([17]dieneN₄); tetraazacyclooctadecadiene ([18]dieneN₄);tetraazacyclononadecadiene ([19]dieneN₄); tetraazacycloeicosadiene([20]dieneN₄); tetraazacyclooctatetradiene ([8]tetradieneN₄);tetraazacyclononatetradiene ([9]tetradieneN₄);tetraazacyclodecatetradiene ([10]tetradieneN₄);tetraazacycloundecatetradiene ([11]tetradieneN₄);tetraazacyclododecatetradiene ([12]tetradieneN₄);tetraazacyclotridecatetradiene ([13]tetradieneN₄);tetraazacyclotetradecatetradiene ([14]tetradieneN₄);tetraazacyclopentadecatetradiene ([15]tetradieneN₄);tetraazacyclohexadecatetradiene ([16]tetradieneN₄);tetraazacycloheptadecatetradiene ([17]tetradieneN₄);tetraazacyclooctadecatetradiene ([18]tetradieneN₄);tetraazacyclononadecatetradiene ([19]tetradieneN₄); andtetraazacycloeicosatetradiene ([20]tetradieneN₄).

N Valence Stabilizer #13d: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:hexaazacyclododecane ([12]aneN₆); hexaazacyclotridecane ([13]aneN₆);hexaazacyclotetradecane ([14]aneN₆); hexaazacyclopentadecane([15]aneN₆); hexaazacyclohexadecane ([16]aneN₆); hexaazacycloheptadecane([17]aneN₆); hexaazacyclooctadecane ([18]aneN₆); hexaazacyclononadecane([19]aneN₆); hexaazacycloeicosane ([20]aneN₆); hexaazacycloheneicosane([21]aneN₆); hexaazacyclodocosane ([22]aneN₆); hexaazacyclotricosane([23]aneN₆); hexaazacyclotetracosane ([24]aneN₆);hexaazacyclododecatriene ([12]trieneN₆); hexaazacyclotridecatriene([13]trieneN₆); hexaazacyclotetradecatriene ([14]trieneN₆);hexaazacyclopentadecatriene ([15]trieneN₆); hexaazacyclohexadecatriene([16]trieneN₆); hexaazacycloheptadecatriene ([17]trieneN₆);hexaazacyclooctadecatriene ([18]trieneN₆); hexaazacyclononadecatriene([19]trieneN₆); hexaazacycloeicosatriene ([20]trieneN₆);hexaazacycloheneicosatriene ([21]trieneN₆); hexaazacyclodocosatriene([22]trieneN₆); hexaazacyclotricosatriene ([23]trieneN₆); andhexaazacyclotetracosatriene ([24]trieneN₆).

N Valence Stabilizer #13e: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:octaazacyclohexadecane ([16]aneN₈); octaazacycloheptadecane ([17]aneN₈);octaazacyclooctadecane ([18]aneN₈); octaazacyclononadecane ([19]aneN₈);octaazacycloeicosane ([20]aneN₈); octaazacycloheneicosane ([21]aneN₈);octaazacyclodocosane ([22]aneN₈); octaazacyclotricosane ([23]aneN₈);octaazacyclotetracosane ([24]aneN₈); octaazacyclohexadecatetradiene([16]tetradieneN₈); octaazacycloheptadecatetradiene ([17]tetradieneN₈);octaazacyclooctadecatetradiene ([18]tetradieneN₈);octaazacyclononadecatetradiene ([19]tetradieneN₈);octaazacycloeicosatetradiene ([20]tetradieneN₈);octaazacycloheneicosatetradiene ([21]tetradieneN₈);octaazacyclodocosatetradiene ([22]tetradieneN₈);octaazacyclotricosatetradiene ([23]tetradieneN₈); andoctaazacyclotetracosatetradiene ([24]tetradieneN₈).

N Valence Stabilizer #13f: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:decaazacycloeicosane ([20]aneN₁₀); decaazacycloheneicosane ([21]aneN₁₀);decaazacyclodocosane ([22]aneN₁₀); decaazacyclotricosane ([23]aneN₁₀);decaazacyclotetracosane ([24]aneN₁₀); decaazacyclopentacosane([25]aneN₁₀); decaazacyclohexacosane ([26]aneN₁₀);decaazacycloheptacosane ([27]aneN₁₀); decaazacyclooctacosane([28]aneN₁₀); decaazacyclononacosane ([29]aneN₁₀);decaazacyclotriacontane ([30]aneN₁₀); decaazacycloeicosapentadiene([20]pentadieneN₁₀); decaazacycloheneicosapentadiene([21]pentadieneN₁₀); decaazacyclodocosapentadiene ([22]pentadieneN₁₀);decaazacyclotricosapentadiene ([23]pentadieneN₁₀ );decaazacyclotetracosapentadiene ([24]pentadieneN₁₀);decaazacyclopentacosapentadiene ([25]pentadieneN₁₀);decaazacyclohexacosapentadiene ([26]pentadieneN₁₀);decaazacycloheptacosapentadiene ([27]pentadieneN₁₀);decaazacyclooctacosapentadiene ([28]pentadieneN₁₀);decaazacyclononacosapentadiene ([29]pentadieneN₁₀); anddecaazacyclotriacontapentadiene ([30]pentadieneN₁₀).

N Valence Stabilizer #14a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of nitrogen and are contained in component 5-memberedheterocyclic rings (N—N Tetradentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: porphyrins (including tetraphenylporphine (tpp); “picketfence” porphyrins, “picket tail” porphyrins, “bispocket” porphyrins,“capped” porphyrins, cyclophane porphyrins, “pagoda” porphyrins,“pocket” porphyrins, “pocket tail” porphyrins, cofacial diporphyrins,“strapped” porphyrins, “hanging base” porphyrins, bridged porphyrins,chelated mesoporphyrins, homoporphyrins, chlorophylls, and pheophytins);porphodimethanes; porphyrinogens; chlorins; bacteriochlorins;isobacteriochlorins; corroles; corrins and corrinoids; didehydrocorrins;tetradehydrocorrins; hexadehydrocorrins; octadehydrocorrins;tetraoxazoles; tetraisooxazoles; tetrathiazoles; tetraisothiazoles;tetraazaphospholes; tetraimidazoles; tetrapyrazoles; tetraoxadiazoles;tetrathiadiazoles; tetradiazaphospholes; tetratriazoles;tetraoxatriazoles; tetrathiatriazoles; coproporphyrin; etioporphyrin;and hematoporphyrin.

N Valence Stabilizer #14b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof nitrogen and are contained in component 5-membered heterocyclic rings(N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: hexaphyrins (hexapyrroles);hexaoxazoles; hexaisooxazoles; hexathiazoles; hexaisothiazoles;hexaazaphospholes; hexaimidazoles; hexapyrazoles; hexaoxadiazoles;hexathiadiazoles; hexadiazaphospholes; hexatriazoles; hexaoxatriazoles;and hexathiatriazoles.

N Valence Stabilizer #14c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of nitrogen and are contained in component 5-memberedheterocyclic rings (N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: octaphyrins(octapyrroles); octaoxazoles; octaisooxazoles; octathiazoles;octaisothiazoles; octaazaphospholes; octaimidazoles; octapyrazoles;octaoxadiazoles; octathiadiazoles; octadiazaphospholes; octatriazoles;octaoxatriazoles; and octathiatriazoles.

N Valence Stabilizer #14d: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof nitrogen and are contained in component 5-membered heterocyclic rings(N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: decaphyrins (decapyrroles);decaoxazoles; decaisooxazoles; decathiazoles; decaisothiazoles;decaazaphospholes; decaimidazoles; decapyrazoles; decaoxadiazoles;decathiadiazoles; decadiazaphospholes; decatriazoles; decaoxatriazoles;and decathiatriazoles.

N Valence Stabilizer #15a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tetradentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: porphyrazines;octahydrodiazaporphyrins; phthalocyanines; naphthalocyanines;anthracocyanines; and tetraazaporphyrins.

N Valence Stabilizer #15b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazahexaphyrins; tetraazahexaphyrins; hexaazahexaphyrins;diazahexapyrazoles; tetraazahexapyrazoles; hexaazahexapyrazoles;diazahexaimidazoles; tetraazahexaimidazoles; and hexaazahexaimidazoles.

N Valence Stabilizer #15c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazaoctaphyrins; tetraazaoctaphyrins; hexaazaoctaphyrins;octaazaoctaphyrins; diazaoctapyrazoles; tetraazaoctapyrazoles;hexaazaoctapyrazoles; octaazaoctapyrazoles; diazaoctaimidazoles;tetraazaoctaimidazoles; hexaazaoctaimidazoles; andoctaazaoctaimidazoles.

N Valence Stabilizer #15d: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazadecaphyrins; tetraazadecaphyrins; hexaazadecaphyrins;octaazadecaphyrins; decaazadecaphyrins; diazadecapyrazoles;tetraazadecapyrazoles; hexaazadecapyrazoles; octaazadecapyrazoles;decaazadecapyrazoles; diazadecaimidazoles; tetraazadecaimidazoles;hexaazadecaimidazoles; octaazadecaimidazoles; and decaazadecaimidazoles.

N Valence Stabilizer #16a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of nitrogen and are contained in component 6-memberedheterocyclic rings (N—N Tetradentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: cyclotetrapyridines; cyclotetraoxazines;cyclotetrathiazines; cyclotetraphosphorins; cyclotetraquinolines;cyclotetrapyrazines; cyclotetrapyridazines; cyclotetrapyrimidines;cyclotetraoxadiazines; cyclotetrathiadiazines;cyclotetradiazaphosphorins; cyclotetraquinoxalines; cyclotetratriazines;cyclotetrathiatriazines; and cyclotetraoxatriazines.

N Valence Stabilizer #16b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof nitrogen and are contained in component 6-membered heterocyclic rings(N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: cyclosexipyridines; cyclosexioxazines;cyclosexithiazines; cyclosexiphosphorins; cyclosexiquinolines;cyclosexipyrazines; cyclosexipyridazines; cyclosexipyrimidines;cyclosexioxadiazines; cyclosexithiadiazines; cyclosexidiazaphosphorinscyclosexiquinoxalines; cyclosexitriazines; cyclosexithiatriazines; andcyclosexioxatriazines.

N Valence Stabilizer #16c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof nitrogen and are contained in component 6-membered heterocyclic rings(N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: cyclooctapyridines; cyclooctaoxazines;cyclooctathiazines; cyclooctaphosphorins; cyclooctaquinolines;cyclooctapyrazines; cyclooctapyridazines; cyclooctapyrimidines;cyclooctaoxadiazines; cyclooctathiadiazines; cyclooctadiazaphosphorins;cyclooctaquinoxalines; cyclooctatriazines; cyclooctathiatriazines; andcyclooctaoxatriazines.

N Valence Stabilizer #16d: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof nitrogen and are contained in component 6-membered heterocyclic rings(N—N Tridentates, N—N Tetradentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: cyclodecapyridines; cyclodecaoxazines;cyclodecathiazines; cyclodecaphosphorins; cyclodecaquinolines;cyclodecapyrazines; cyclodecapyridazines; cyclodecapyrimidines;cyclodecaoxadiazines; cyclodecathiadiazines; cyclodecadiazaphosphorins;cyclodecaquinoxalines; cyclodecatriazines; cyclodecathiatriazines; andcyclodecaoxatriazines.

N Valence Stabilizer #17a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tetradentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: diazacyclotetrapyridines;tetraazacyclotetrapyridines; diazacyclotetraquinolines;tetraazacyclotetraquinolines; diazacyclotetrapyrazines;tetraazacyclotetrapyrazines; diazacyclotetrapyridazines;tetraazacyclotetrapyridazines; diazacyclotetrapyrimidines;tetraazacyclotetrapyrimidines; diazacyclotetratriazines; andtetraazacyclotetratriazines.

N Valence Stabilizer #17b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazacyclosexipyridines; triazacyclosexipyridines;diazacyclosexiquinolines; triazacyclosexiquinolines;diazacyclosexipyrazines; triazacyclosexipyrazines;diazacyclosexipyridazines; triazacyclosexipyridazines;diazacyclosexipyrimidines; triazacyclosexipyrimidines;diazacyclosexitriazines; and triazacyclosexitriazines.

N Valence Stabilizer #17c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazacyclooctapyridines; tetraazacyclooctapyridines;diazacyclooctaquinolines; tetraazacyclooctaquinolines;diazacyclooctapyrazines; tetraazacyclooctapyrazines;diazacyclooctapyridazines; tetraazacyclooctapyridazines;diazacyclooctapyrimidines; tetraazacyclooctapyrimidines;diazacyclooctatriazines; and tetraazacyclooctatriazines.

N Valence Stabilizer #17d: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazacyclodecapyridines; pentaazacyclodecapyridines;diazacyclodecaquinolines; pentaazacyclodecaquinolines;diazacyclodecapyrazines; pentaazacyclodecapyrazines;diazacyclodecapyridazines; pentaazacyclodecapyridazines;diazacyclodecapyrimidines; pentaazacyclodecapyrimidines;diazacyclodecatriazines; and pentaazacyclodecatriazines.

N Valence Stabilizer #18: Examples of amidines and diamidines (N—Nbidentates or N—N Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N,N′-dimethylformamidine; N,N′-diethylformamidine;N,N′-diisopropylformamidine; N,N′-dibutylformamidine;N,N′-diphenylformamidine; N,N′-dibenzylformamidine;N,N′-dinaphthylformamidine; N,N′-dicyclohexylformamidine;N,N′-dinorbornylformamidine; N,N′-diadamantylformamidine;N,N′-dianthraquinonylformamidine; N,N′-dimethylacetamidine;N,N′-diethylacetamidine; N,N′-diisopropylacetamidine;N,N′-dibutylacetamidine; N,N′-diphenylacetamidine;N,N′-dibenzylacetamidine; N,N′-dinaphthylacetamidine;N,N′-dicyclohexylacetamidine; N,N′-dinorbornylacetamidine;N,N′-diadamantylacetamidine; N,N′-dimethylbenzamidine;N,N′-diethylbenzamidine; N,N′-diisopropylbenzamidine;N,N′-dibutylbenzamidine; N,N′-diphenylbenzamidine;N,N′-dibenzylbenzamidine; N,N′-dinaphthylbenzamidine;N,N′-dicyclohexylbenzamidine; N,N′-dinorbornylbenzamidine;N,N′-diadamantylbenzamidine; N,N′-dimethyltoluamidine;N,N′-diethyltoluamidine; N,N′-diisopropyltoluamidine;N,N′-dibutyltoluamidine; N,N′-diphenyltoluamidine;N,N′-dibenzyltoluamidine; N,N′-dinaphthyltoluamidine;N,N′-dicyclohexyltoluamidine; N,N′-dinorbornyltoluamidine;N,N′-diadamantyltoluamidine; oxalic diamidine; malonic diamidine;succinic diamidine; glutaric diamidine; adipic diamidine; pimelicdiamidine; suberic diamidine; phthalic diamidine; terephthalicdiamidine; isophthalic diamidine; piperazine diamidine;2-iminopyrrolidine; 2-iminopiperidine; amidinobenzamide; benzamidine;chloroazodin; and debrisoquin.

N Valence Stabilizer #19: Examples of biguanides (imidodicarbonimidicdiamides), 20 biguanidines, imidotricarbonimidic diamides,imidotetracarbonimidic diamides, dibiguanides, bis(biguanidines),polybiguanides, and poly(biguanidines) (N—N bidentates, N—N tridentates,N—N tetradentates, and N—N hexadentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: biguanide (bigH); biguanidine, methylbiguanide;ethylbiguanide; isopropylbiguanide; butylbiguanide; benzylbiguanide;phenylbiguanide; tolylbiguanide; naphthylbiguanide; cyclohexylbiguanide;norbornylbiguanide; adamantylbiguanide; dimethylbiguanide;diethylbiguanide; diisopropylbiguanide; dibutylbiguanide;dibenzylbiguanide; diphenylbiguanide; ditolylbiguanide;dinaphthylbiguanide; dicyclohexylbiguanide; dinorbornylbiguanide;diadamantylbiguanide; ethylenedibiguanide; propylenedibiguanide;tetramethylenedibiguanide; pentamethylenedibiguanide;hexamethylenedibiguanide; heptamethylenedibiguanide;octamethylenedibiguanide; phenylenedibiguanide; piperazinedibiguanide;oxalyldibiguanide; malonyldibiguanide; succinyldibiguanide;glutaryldibiguanide; adipyldibiguanide; pimelyldibiguanide;suberyldibiguanide; phtbalyldibiguanide; paludrine; polyhexamethylenebiguanide; 2-guanidinothiazole; 2-guanidinooxazole;2-guanidinoimidazole; 3-guanidinopyrazole; 3-guanidino-1,2,4-triazole;5-guanidinotetrazole; alexidine; buformin; and moroxydine.

N Valence Stabilizer #20: Examples of diamidinomethanes,bis(diamidinomethanes), and poly(diamidinomethanes) (N—N bidentates, N—Ntridentates, N—N tetradentates, and N—N hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: diamidinomethane;N-methyldiamidinomethane; N-ethyldiamidinomethane;N-isopropyldiamidinomethane; N-butyldiamidinomethane;N-benzyldiamidinomethane; N-phenyldiamidinomethane;N-tolyldiamidinomethane; N-naphthyldiamidinomethane;N-cyclohexyldiamidinomethane; N-norbornyldiamidinomethane;N-adamantyldiamidinomethane; dimethyldiamidinomethane;diethyldiamidinomethane; diisopropyldiamidinomethane;dibutyldiamidinomethane; dibenzyldiamidinomethane;diphenyldiamidinomethane; ditolyldiamidinomethane;dinaphthyldiamidinomethane; dicyclohexyldiamidinomethane;dinorbornyldiamidinomethane; diadamantyldiamidinomethane;ethylenebisdiamidinomethane; propylenebisdiamidinomethane;tetramethylenebisdiamidinomethane; pentamethylenebisdiamidinomethane;hexamethylenebisdiamidinomethane; heptamethylenebisdiamidinomethane;octamethylenebisdiamidinomethane; phenylenebisdiamidinomethane;piperazinebisdiamidinomethane; oxalylbisdiamidinomethane;malonylbisdiamidinomethane; succinylbisdiamidinomethane;glutarylbisdiamidinomethane; phthalylbisdiamidinomethane;2-amidinomethylthiazole; 2-amidinomethyloxazole;2-amidinomethylimidazole; 3-amidinomethylpyrazole;3-amidinomethyl-1,2,4-triazole; and 5-amidinomethyltetrazole.

N Valence Stabilizer #21: Examples of imidoylguanidines,amidinoguanidines, bis(imidoylguanidines), bis(amidinoguanidines),poly(imidoylguanidines), and poly(amidinoguanidines) (N—N bidentates,N—N tridentates, N—N tetradentates, and N—N hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: acetimidoylguanidine; amidinoguanidine,benzimidoylguanidine; cyclohexylimidoylguanidine;pentafluorobenzimidoylguanidine; 2-N-imidoylaminothiazole;2-N-imidoylaminooxazole; 2-N-imidoylaminoimidazole;3-N-imidoylaminopyrazole; 3-N-imidoylamino-1,2,4-triazole; and5-N-imidoylaminotetrazole.

N Valence Stabilizer #22: Examples of diformamidine oxides(dicarbonimidic diamides), tricarbonimidic diamides, tetracarbonimidicdiamides, bis(diformamidine oxides), and poly(diformamidine oxides) (N—Nbidentates, N—N tridentates, or N—N tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: diformamidine oxide;methyldiformamidine oxide; ethyldiformamidine oxide;isopropyldiformamidine oxide; butyldiformamidine oxide;benzyldiformamidine oxide; phenyldiformamidine oxide; tolyldiformamidineoxide; naphthyldiformamidine oxide; cyclohexyldiformamidine oxide;norbornyldiformamidine oxide; adamantyldiformamidine oxide;dimethyldiformamidine oxide; diethyldiformamidine oxide;diisopropyldiformamidine oxide; dibutyldiformamidine oxide;dibenzyldiformamidine oxide; diphenyldiformamidine oxide;ditolyldiformamidine oxide; dinaphthyldiformamidine oxide;dicyclohexyldifornamidine oxide; dinorbornyldiformamidine oxide;diadamantyldiformamidine oxide; 2-O-amidinohydroxythiazole;2-O-amidinohydroxyoxazole; 2-O-amidinohydroxyimidazole;3-O-amidinohydroxypyrazole; 3-O-amidinohydroxy-1,2,4-triazole; and5-O-amidinohydroxytetrazole.

N Valence Stabilizer #23: Examples of diformamidine sulfides(thiodicarbonimidic diamides), thiotricarbonimidic diamides,thiotetracarbonimidic diamides, bis(diformamidine sulfides), andpoly(diformamidine sulfides) (N—N bidentates, N—N tridentates, or N—Ntetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: diformamidinesulfide; methyldiformamidine sulfide; ethyldiformamidine sulfide;isopropyldiformamidine sulfide; butyldiformamidine sulfide;benzyldiformamidine sulfide; phenyldiformamidine sulfide;tolyldiformamidine sulfide; naphthyldiformamidine sulfide;cyclohexyldiformamidine sulfide; norbornyldiformamidine sulfide;adamantyldiformamidine sulfide; dimethyldiformamidine sulfide;diethyldiformamidine sulfide; diisopropyldiformamidine sulfide;dibutyldiformamidine sulfide; dibenzyldiformamidine sulfide;diphenyldiformamidine sulfide; ditolyldiformamidine sulfide;dinaphthyldiformamidine sulfide; dicyclohexyldiformamidine sulfide;dinorbornyldiformamidine sulfide; diadamantyldiformamidine sulfide;phenylthiobisformamidine; 2-S-amidinomercaptothiazole;2-S-amidinomercaptooxazole; 2-S-amidinomercaptoimidazole;3-S-amidinomercaptopyrazole; 3-S-amidinomercapto-1,2,4-triazole; and5-S-amidinomercaptotetrazole.

N Valence Stabilizer #24: Examples of imidodicarbonimidic acids,diimidodicarbonimidic acids, imidotricarbonimidic acids,imidotetracarbonimidic acids, and derivatives thereof (N—N Bidentates,N—N Tridentates, N—N Tetradentates, and N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: imidodicarbonimidic acid,diimidodicarbonimidic acid, imidotricarbonimidic acid,imidotetracarbonimidic acid; O-methylimidodicarbonimidic acid;O-ethylimidodicarbonimidic acid; O-isopropylimidodicarbonimidic acid;O-phenylimidodicarbonimidic acid; O-benzylimidodicarbonimidic acid;O-cyclohexylimidodicarbonimidic acid; O-naphthylimidodicarbonimidicacid; O-norbornylimidodicarbonimidic acid;O-adamantylimidodicarbonimidic acid; O,O′-dimethylimidodicarbonimidicacid; O,O′-diethylimidodicarbonimidic acid;O,O′-diisopropylimidodicarbonimidic acid;O,O′-diphenylimidodicarbonimidic acid; O,O′-dibenzylimidodicarbonimidicacid; O,O′-dicyclohexylimidodicarbonimidic acid;O,O′-dinaphthylimidodicarbonimidic acid;O,O′-dinorbornylimidodicarbonimidic acid; andO,O′-diadamantylimidodicarbonimidic acid.

N Valence Stabilizer #25: Examples of thioimidodicarbonimidic acids,thiodiimidodicarbonimidic acids, thioimidotricarbonimidic acids,thioimidotetracarbonimidic acids, and derivatives thereof (N—NBidentates, N—N Tridentates, N—N Tetradentates, and N—N Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: thioimidodicarbonimidic acid,thiodiimidodicarbonimidic acid, thioimidotricarbonimidic acid,thioimidotetracarbonimidic acid; O-methylthioimidodicarbonimidic acid;O-ethylthioimidodicarbonimidic acid; O-isopropylthioimidodicarbonimidicacid; O-phenylthioimidodicarbonimidic acid;O-benzylthioimidodicarbonimidic acid;O-cyclohexylthioimidodicarbonimidic acid;O-naphthylthioimidodicarbonimidic acid;O-norbornylthioimidodicarbonimidic acid;O-adamantylthioimidodicarbonimidic acid;O,O′-dimethylthioimidodicarbonimidic acid;O,O′-diethylthioimidodicarbonimidic acid;O,O′-diisopropylthioimidodicarbonimidic acid;O,O′-diphenylthioimidodicarbonimidic acid;O,O′-dibenzylthioimidodicarbonimidic acid;O,O′-dicyclohexylthioimidodicarbonimidic acid;O,O′-dinaphthylthioimidodicarbonimidic acid;O,O′-dinorbornylthioimidodicarbonimidic acid; andO,O′-diadamantylthioimidodicarbonimidic acid.

N Valence Stabilizer #26: Examples of diimidoylimines,diimidoylhydrazides, bis(diimidoylimines), bis(diimidoylhydrazides),poly(diimidoylimines), and poly(diimidoylhydrazides) (N—N Tridentatesand N—N Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diacetimidoylimine; dibenzimidoylimine; and dicyclohexylimidoylimine.

N Valence Stabilizer #27: Examples of imidosulfamides,diimidosulfamides, bis(imidosulfamides), bis(diimidosulfamides),poly(imidosulfamides), and poly(diimidosulfamides) (N—N Bidentates, N—NTridentates, N—N Tetradentates, and N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: imidosulfamidic acid, diimidosulfamidicacid; O-phenylimidosulfamide; O-benzylimidosulfamide;N-phenylimidosulfamide; N-benzylimidosulfamide;O-phenyldiimidosulfamide; O-benzyldiimidosulfamide;N-phenyldiimidosulfamide; and N-benzyldiimidosulfamide.

N Valence Stabilizer #28: Examples of phosphoramidimidic triamides,bis(phosphoramidimidic triamides), and poly(phosphoramidimidictriamides) and derivatives thereof (N—N Bidentates, N—N Tridentates, N—NTetradentates, and N—N Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphoramidimidic triamide; N-phenylphosphoramidimidic triamide;N-benzylphosphoramidimidic triamide; N-naphthylphosphoramidimidictriamide; N-cyclohexylphosphoramidimidic triamide;N-norbornylphosphoramidimidic triamide; N,N′-diphenylphosphoramidimidictriamide; N,N′-dibenzylphosphoramidimidic triamide;N,N′-dinaphthylphosphoramidimidic triamide;N,N′-dicyclohexylphosphoramidimidic triamide; andN,N′-dinorbornylphosphoramidimidic triamide.

N Valence Stabilizer #29: Examples of phosphoramidimidic acid,phosphorodiamidimidic acid, bis(phosphoramidimidic acid),bis(phosphorodiamidimidic acid), poly(phosphoramidimidic acid),poly(phosphorodiamidimidic acid), and derivatives thereof (N—NBidentates, N—N Tridentates, N—N Tetradentates, and N—N Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: phosphoramidimidic acid,phosphorodiamidimidic acid, O-phenylphosphoramidimidic acid;O-benzylphosphoramidimidic acid; O-naphthylphosphoramidimidic acid;O-cyclohexylphosphoramidimidic acid; O-norbornylphosphoramidimidic acid;O,O′-diphenylphosphoramidimidic acid; O,O′-dibenzylphosphoramidimidicacid; O,O′-dinaphthylphosphoramidimidic acid;O,O′-dicyclohexylphosphoramidimidic acid; andO,O′-dinorbornylphosphoramidimidic acid.

N Valence Stabilizer #30: Examples of phosphoramidimidodithioic acid,phosphorodiamidimidothioic acid, bis(phosphoramidimidodithioic acid),bis(phosphorodiamidimidothioic acid), poly(phosphoramidimidodithioicacid), poly(phosphorodiamidimidothioic acid), and derivatives thereof(N—N Bidentates, N—N Tridentates, N—N Tetradentates, and N—NHexadentates) that meet the requirements for use as “4wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:phosphoramidimidodithioic acid, phosphorodiamidimidothioic acid,S-phenylphosphoramidimidodithioic acid; S-benzylphosphoramidimidodithoicacid; S-naphthylphosphoramidimidodithioic acid;S-cyclohexylphosphoramidimidodithioic acid;S-norbornylphosphoramidimidodithioic acid;S,S′-diphenylphosphoramidimidodithioic acid;S,S′-dibenzylphosphoramidimidodithioic acid;S,S′-dinaphthylphosphoramidimidodithioic acid;S,S′-dicyclohexylphosphoramidimidodithioic acid; andS,S′-dinorbornylphosphoramidimidodithioic acid.

N Valence Stabilizer #31: Examples of azo compounds with amino, imino,oximo, diazeno, or hydrazido substitution at the ortho- (for aryl) oralpha- or beta- (for alkyl) positions, bis[o-(H₂N-) or alpha- orbeta-(H₂N-)azo compounds], or poly[o-(H₂N-) or alpha- or beta-(H₂N-)azocompounds) (N—N Bidentates, N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: o-aminoazobenzene;o,o′-diaminoazobenzene; (2-pyridine)azobenzene;1-phenylazo-2-naphthylamine; pyridineazo-2-naphthol (PAN);pyridineazoresorcinol (PAR);o-hydroxy-o′-(beta-aminoethylamino)azobenzene; Benzopurpurin 4B; CongoRed; Fat Brown RR; benzopurpurin; Congo Red; Direct Red 75; MordantBrown 48; Nitro Red; 2-imidazolylazobenzene; 2-benzimidazolylazobenzene;3-pyrazolylazobenzene; 3-(1,2,4-triazolyl)azobenzene;2-pyridylazobenzene; 2-pyrazinylazobenzene; and 2-pyrimidinylazobenzene.

N Valence Stabilizer #32: Examples of diazeneformimidamides(diazeneamidines), diazeneacetimidamides(diazene-alpha-amidinoalkanes(alkenes)), bis(diazeneformimidamides),bis(diazeneacetimidamides), poly(diazeneformimidamides), andpoly(diazeneacetimidamides) (N—N Bidentates, N—N Tetradentates, and N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:diazeneformimidamide (diazeneamidine); diazeneacetimidamide(diazene-alpha-amidinomethane); phenyldiazeneformimidamide;triphenyldiazeneformimidamide; phenyldiazeneacetimidamide; andtriphenyldiazeneacetimidamide.

N Valence Stabilizer #33: Examples of diazeneformimidic acid,diazeneacetimidic acid, bis(diazeneformimidic acid),bis(diazeneacetimidic acid), poly(diazeneformimidic acid),poly(diazeneacetimidic acid), and derivatives thereof (N—N Bidentates,N—N Tetradentates, and N—N Hexadentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazeneformimidic acid, diazeneacetimidic acid,phenyldiazeneformimidic acid, diphenyldiazeneformimidic acid,phenyldiazeneacetimidic acid, and diphenyldiazeneacetimidic acid.

N Valence Stabilizer #34: Examples of diazeneformimidothioic acid,diazeneacetimidothioic acid, bis(diazeneformimidothioic acid),bis(diazeneacetimidothioic acid), poly(diazeneformimidothioic acid),poly(diazeneacetimidothioic acid), and derivatives thereof (N—NBidentates, N—N Tetradentates, and N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: diazeneformimidothioic acid,diazeneacetimidothioic acid, phenyldiazeneformimidothioic acid,diphenyldiazeneformimidothioic acid, phenyldiazeneacetimidothioic acid,and diphenyldiazeneacetimidothioic acid.

N Valence Stabilizer #35: Examples of imidoyldiazenes,bis(imidoyldiazenes), and poly(imidoyldiazenes), (N—N Tridentates andN—N Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:acetimidoyldiazene; benzimidoyldiazene; and cyclohexylimidoyldiazene.

N Valence Stabilizer #36: Examples of diazenediformimidamides(1,2-diazenediamidines), diazenediacetimidamides(1,2-diazene-di-alpha-amidinoalkanes(alkenes)),bis(diazenediformimidamides), bis(diazenediacetimidamides),poly(diazenediformimidamides), and poly(diazenediacetimidamides) (N—NTridentates and N—N Hexadentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazenediformimidamide (1,2-diazenediamidine),diazenediacetimidamide (1,2-diazene-di-alpha-amidinomethane);diphenyldiazenediformimidamide; tetraphenyldiazenediformimidamide;diphenyldiazenediacetimidamide; and tetraphenyldiazenediacetimidamide.

N Valence Stabilizer #37: Examples of diazenediformimidic acid,diazenediacetimidic acid, bis(diazenediformimidic acid),bis(diazenediacetimidic acid), poly(diazenediformimidic acid), andpoly(diazenediacetimidic acid), and derivatives thereof (N—N Tridentatesand N—N Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diazenediformimidic acid, diazenediacetimidic acid,diphenyldiazenediformimidic acid, and diphenyldiazenediacetimidic acid.

N Valence Stabilizer #38: Examples of diazenediformimidothioic acid,diazenediacetimidothioic acid, bis(diazenediformimidothioic acid),bis(diazenediacetimidothioic acid), poly(diazenediformimidothioic acid),and poly(diazenediacetimidothioic acid), and derivatives thereof (N—NTridentates and N—N Hexadentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazenediformimidothioic acid, diazenediacetimidothioic acid,diphenyldiazenediformimidothioic acid, anddiphenyldiazenediacetimidothioic acid.

N Valence Stabilizer #39: Examples of diimidoyldiazenes,bis(diimidoyldiazenes), and poly(diimidoyldiazenes), (N—N Tridentatesand N—N Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diacetimidoyldiazene; dibenzimidoyldiazene; anddicyclohexylimidoyldiazene.

N Valence Stabilizer #40: Examples of ortho-amino (or -hydrazido)substituted formazans, bis(o-amino or -hydrazido substituted formazans),and poly(o-amino or -hydrazido substituted formazans) (N—N Bidentates,N—N Tridentates, N—N Tetradentates, and N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 1-(2-aminophenyl)-3,5-diphenylformazan;and 1,5-bis(2-aminophenyl)-3-phenylformazan.

N Valence Stabilizer #41: Examples of ortho-amino (or -hydrazido)substituted azines (including ketazines), bis(o-amino or hydrazidosubstituted azines), and poly(o-amino or hydrazido substituted azines)(N—N Bidentates, N—N Tridentates, N—N Tetradentates, and N—NHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:2-amino-1-benzalazine; 2-amino-1-naphthalazine; and2-amino-1-cyclohexanonazine.

N Valence Stabilizer #42: Examples of Schiff Bases with one Imine (C═N)Group and with ortho- or alpha- or beta-amino or imino or oximo ordiazeno or hydrazido substitution (N—N Bidentates, N—N Tridentates, N—NTetradentates, N—N Pentadentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N-(2-Aminobenzaldehydo)isopropylamine;N-(2-Pyridinecarboxaldehydo)isopropylamine;N-(2-Pyrrolecarboxaldehydo)isopropylamine;N-(2-Acetylpyridino)isopropylamine; N-(2-Acetylpyrrolo)isopropylamine;N-(2-Aminoacetophenono)isopropylamine;N-(2-Aminobenzaldehydo)cyclohexylamine;N-(2-Pyridinecarboxaldehydo)cyclohexylamine;N-(2-Pyrrolecarboxaldehydo)cyclohexylamine;N-(2-Acetylpyridino)cyclohexylamine; N(2-Acetylpyrrolo)cyclohexylamine;N-(2-Aminoacetophenono)cyclohexylamine; N-(2-Aminobenzaldehydo)aniline;N-(2-Pyridinecarboxaldehydo)aniline; N-(2-Pyrrolecarboxaldehydo)aniline;N-(2-Acetylpyridino)aniline; N-(2-Acetylpyrrolo)aniline;N-(2-Aminoacetophenono)aniline; N-(2-Aminobenzaldehydo)aminonorbornane;N-(2-Pyridinecarboxaldehydo)aminonorbornane;N-(2-Pyrrolecarboxaldehydo)aminonorbornane;N-(2-Acetylpyridino)aminonorbornane; N-(2-Acetylpyrrolo)aminonorbornane;N-(2-Aminoacetophenono)aminonorbornane; 2-pyrrolecarboxaldehydephenylhydrazone; 2-pyrrolecarboxaldehyde 2-pyridyl hydrazone;2-aminobenzaldehyde phenylhydrazone (nitrin); and 2-aminobenzaldehyde2-pyridyl hydrazone. Also includes hydrazones with ortho-N substitution.

N Valence Stabilizer #43: Examples of Schiff Bases with two Imine (C═N)Groups and without ortho- (for aryl constituents) or alpha- or beta-(for alkyl constituents) hydroxy, carboxy, carbonyl, thiol, mercapto,thiocarbonyl, amino, imino, oximo, diazeno, or hydrazido substitution(N—N Bidentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N,N′-(Glyoxalo)diisopropylamine; N,N′-(Glyoxalo)dicyclohexylamine;N,N′-(Glyoxalo)dianiline; N,N′-(Glyoxalo)di-aminonorbornane;N,N′-(Malondialdehydo)diisopropylamine;N,N′-(Malondialdehydo)dicyclohexylamine;N,N′-(Malondialdehydo)dianiline;N,N′-(Malondialdehydo)di-aminonorbornane;N,N′-(Phthalicdialdehydo)diisopropylamine;N,N′-(Phthalicdialdehydo)dicyclohexylamine;N,N′-(Phthalicdialdehydo)dianiline;N,N′-(Phthalicdialdehydo)di-aminonorbornane;N,N′-(Formylcamphoro)diisopropylamine;N,N′-(Formylcamphoro)dicyclohexylamine; N,N′-(Formylcamphoro)dianiline;N,N′-(Formylcamphoro)di-aminonorbornane;N,N′-(Acetylacetonato)diisopropylamine;N,N′-(Acetylacetonato)dicyclohexylamine;N,N′-(Acetylacetonato)dianiline;N,N′-(Acetylacetonato)di-aminonorbornane;N,N′-(Diacetylbenzeno)diisopropylamine;N,N′-(Diacetylbenzeno)dicyclohexylamine;N,N′-(Diacetylbenzeno)dianiline;N,N′-(Diacetylbenzeno)di-aminonorbornane;N,N′-(1,2-Cyclohexanono)diisopropylamine;N,N′-(1,2-Cyclohexanono)dicyclohexylamine;N,N′-(1,2-Cyclohexanono)dianiline;N,N′-(1,2-Cyclohexanono)di-aminonorbornane;N,N′-(Camphorquinono)diisopropylamine;N,N′-(Camphorquinono)dicyclohexylamine; N,N′-(Camphorquinono)dianiline;N,N′-(Camphorquinono)di-aminonorbornane;N,N′-(Benzaldehydo)ethylenediamine;N,N′-(Naphthaldehydo)ethylenediamine;N,N′-(Acetophenono)ethylenediamine;N,N′-(Benzaldehydo)trimethylenediamine;N,N′-(Naphthaldehydo)trimethylenediamine;N,N′-(Acetophenono)trimethylenediamine;N,N′-(Benzaldehydo)cyclohexane-1,2-diamine;N,N′-(Naphthaldehydo)cyclohexane-1,2-diamine;N,N′-(Acetophenono)cyclohexane-1,2-diamine;N,N′-(Benzaldehydo)-1,2-diaminobenzene;N,N′-(Naphthaldehydo)-1,2-diaminobenzene;N,N′-(Acetophenono)-1,2-diaminobenzene;N,N′-(Acetylacetonato)ethylenediamine;N,N′-(Acetylacetonato)-1,2-cyclohexylenediamine;N,N′-(Acetylacetonato)-1,2-propylenediamine;N,N′-(Glyoxalo)-o-phenylenediamine; and N,N′-(Glyoxalo)ethylenediamine.Also includes dihydrazones.

N Valence Stabilizer #44: Examples of Schiff Bases with two Imine (C═N)Groups and with ortho- or alpha- or beta-amino or imino or oximo ordiazeno or hydrazido substitution (N—N Bidentates, N—N Tridentates, N—NTetradentates, N—N Pentadentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to:N,N′-(2,6-Pyridinedicarboxaldehydo)diisopropylamine;N,N′-(2,6-Pyridinedicarboxaldehydo)dicyclohexylamine;N,N′-(2,6-Pyridinedicarboxaldehydo)dianiline;N,N′-(2,6-Pyridinedicarboxaldehydo)di-aminonorbornane;N,N′-(2,5-Pyrroledicarboxaldehydo)diisopropylamine;N,N′-(2,5-Pyrroledicarboxaldehydo)dicyclohexylamine;N,N′-(2,5-Pyrroledicarboxaldehydo)dianiline;N,N′-(2,5-Pyrroledicarboxaldehydo)di-aminonorbornane;N,N′-(o-Aminophthalicdialdehydo)diisopropylamine;N,N′-(o-Aminophthalicdialdehydo)dicyclohexylamine;N,N′-(o-Aminophthalicdialdehydo)dianiline;N,N′-(o-Aminophthalicdialdehydo)di-aminonorbornane;N,N′-(o-Aminoformylcamphoro)diisopropylamine;N,N′-(o-Aminoformylcamphoro)dicyclohexylamine;N,N′-(o-Aminoformylcamphoro)dianiline;N,N′-(o-Aminoformylcamphoro)di-aminonorbornane;N,N′-(2,6-Diacetylpyridino)diisopropylamine;N,N′-(2,6-Diacetylpyridino)dicyclohexylamine;N,N′-(2,6-Diacetylpyridino)dianiline;N,N′-(2,6-Diacetylpyridino)di-aminonorbornane;N,N′-(o-Aminodiacetylbenzeno)diisopropylamine;N,N′-(o-Aminodiacetylbenzeno)dicyclohexylamine;N,N′-(o-Aminodiacetylbenzeno)dianiline;N,N′-(o-Aminodiacetylbenzeno)di-aminonorbornane;N,N′-(3,6-Diamino-1,2-cyclohexanono)diisopropylamine;N,N′-(3,6-Diamino-1,2-cyclohexanono)dicyclohexylamine;N,N′-(3,6-Diamino-1,2-cyclohexanono)dianiline;N,N′-(3,6-Diamino-1,2-cyclohexanono)di-aminonorbornane;N,N′-(2,5-Diacetylpyrrolo)diisopropylamine;N,N′-(2,5-Diacetylpyrrolo)dicyclohexylamine;N,N′-(2,5-Diacetylpyrrolo)dianiline;N,N′-(2,5-Diacetylpyrrolo)di-aminonorbornane;N,N′-(o-Aminobenzaldehydo)ethylenediamine;N,N′-(o-Aminonaphthaldehydo)ethylenediamine;N,N′-(o-Aminoacetophenono)ethylenediamine;N,N′-(o-Aminobenzaldehydo)trimethylenediamine;N,N′-(o-Aminonaphthaldehydo)trimethylenediamine;N,N′-(o-Aminoacetophenono)trimethylenediamine;N,N′-(o-Aminobenzaldehydo)cyclohexane-1,2-diamine;N,N′-(o-Aminonaphthaldehydo)cyclohexane-1,2-diamine;N,N′-(o-Aminoacetophenono)cyclohexane-1,2-diamine;N,N′-(o-Aminobenzaldehydo)-1,2-diaminobenzene;N,N′-(o-Aminonaphthaldehydo)-1,2-diaminobenzene; andN,N′-(o-Aminoacetophenono)-1,2-diaminobenzene. Also includes hydrazoneswith ortho-N substitution.

N Valence Stabilizer #45: Examples of Schiff Bases with three Imine(C═N) Groups and without ortho- (for aryl constituents) or alpha- orbeta- (for alkyl constituents) hydroxy, carboxy, carbonyl, thiol,mercapto, thiocarbonyl, amino, imino, oximo, diazeno, or hydrazidosubstitution (N—N Tridentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N,N′,N″-(Benzaldehydo)tris(2-aminoethyl)amine;N,N′,N″-(Naphthaldehydo)tris(2-aminoethyl)amine; andN,N′,N″-(Acetophenono)tris(2-aminoethyl)amine. Also includestrihydrazones.

N Valence Stabilizer #46: Examples of Schiff Bases with three Imine(C═N) Groups and with ortho- or alpha- or beta-amino or imino or oximoor diazeno or hydrazido substitution (N—N Tridentates, N—NTetradentates, N—N Pentadentates, or N—N Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to:N,N′,N″-(o-Aminobenzaldehydo)tris(2-aminoethyl)amine;N,N′,N″-(o-Aminonaphthaldehydo)tris(2-aminoethyl)amine; andN,N′,N″-(o-Aminoacetophenono)tris(2-aminoethyl)amine.

S Valence Stabilizer #1: Examples of macrocyclic, macrobicyclic, andmacropolycyclic oligothioketones (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofthioketones (especially in the beta position) (S—S Bidentates, S—STetradentates, and S—S Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: hexathioketocyclotetracosane ([24]ane(=S)₆);hexathioketocycloheneicosane ([21]ane(=S)₆); hexathioketocyclooctadecane([18]ane(=S)₆); hexathioketocyclopentadecane ([15]ane(=S)₆);tetrathioketocycloeicosane ([20]ane(=S)₄); tetrathioketocyclooctadecane([18]ane(=S)₄); tetrathioketocyclohexadecane ([16]ane(=S)₄);tetrathioketocyclotetradecane ([14]ane(=S)₄); tetrathioketocyclododecane([12]ane(=S)₄); dithioketocyclohexadecane ([16]ane(=S)₂);dithioketocyclotetraadecane ([14]ane(=S)₂); dithioketocyclododecane([12]ane(=S)₂); dithioketocyclodecane ([10]ane(=S)₂); anddithioketocyclooctane ([8]ane(=S)₂).

S Valence Stabilizer #2: Examples of macrocyclic, macrobicyclic, andmacropolycyclic dithiolenes (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofalpha-, alpha-dithiolenes (meaning two thiol groups on a single carbonatom in the ring) (S—S Bidentates, S—S Tetradentates, and S—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:hexathiolocyclotetracosane ([24]ane(-SH)₆); hexathiolocycloheneicosane([21]ane(-SH)₆); hexathiolocyclooctadecane ([18]ane(-SH)₆);hexathiolocyclopentadecane ([15]ane(-SH)₆); tetrathiolocycloeicosane([20]ane(-SH)₄); tetrathiolocyclooctadecane ([18]ane(-SH)₄);tetrathiolocyclohexadecane ([16]ane(-SH)₄); tetrathiolocyclotetradecane([14]ane(-SH)₄); tetrathiolocyclododecane ([12]ane(-SH)₄);dithiolocyclohexadecane ([16]ane(-SH)₂); dithiolocyclotetraadecane([14]ane(-SH)₂); dithiolocyclododecane ([12]ane(-SH)₂);dithiolocyclodecane ([10]ane(-SH)₂); and dithiolocyclooctane([8]ane(-SH)₂).

S Valence Stabilizer #3: Examples of dithioimidodialdehydes,dithiohydrazidodialdehydes (thioacyl thiohydrazides),bis(dithioimidodialdehydes), bis(dithiohydrazidodialdehydes),poly(dithioimidodialdehydes), and poly(dithiohydrazidodialdehydes) (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiodiacetamide, dithiodipropanamide,dithiodibutanamide, dithiodibenzamide, and dithiodicyclohexamide.

S Valence Stabilizer #4: Examples of dithioimidodicarbonic acids,dithiohydrazidodicarbonic acids, bis(dithioimidodicarbonic acids),bis(dithiohydrazidodicarbonic acids), poly(dithioimidodicarbonic acids),poly(dithiohydrazidodicarbonic acids) and derivatives thereof (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithioimidodicarbonic acid,dithiohydrazidodicarbonic acid, O-phenyldithioimidodicarbonic acid,O-benzyldithioimidodicarbonic acid, O-cyclohexyldithioimidodicarbonicacid, O-norbornyldithioimidodicarbonic acid,O,O′-diphenyldithioimidodicarbonic acid,O,O′-dibenzyldithioimidodicarbonic acid,O,O′-dicyclohexyldithioimidodicarbonic acid, andO,O′-norbornyldithioimidodicarbonic acid.

S Valence Stabilizer #5: Examples of 1,3-dithioketones(dithio-beta-ketonates), 1,3,5-trithioketones, bis(1,3-dithioketones),and poly(1,3-dithioketones) (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:hexafluoropentanedithione; 1,3-diphenyl-1,3-propanedithione;thiobenzoylthiopinacolone; dithiocyclohexoylmethane;diphenylpentanetrithionate; tetramethylnonanetrithionate;hexafluoroheptanetrithionate; trifluoroheptanetrithionate;1-(2-thienyl)-1,3-butanedithione, 1-(2-naphthyl)-1,3-butanedithione,trifluorothioacetylthiocamphor; and 1,3-indandithione.

S Valence Stabilizer #6: Examples of 1,2-dithioketones (dithiolenes,dithio-alpha-ketonates), 1,2,3-trithioketones, dithiotropolonates,o-dithioquinones, bis(1,2-dithioketones), and poly(1,2-dithioketones)(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiotropolone; 1,2-dithiobenzoquinone(o-dithioquinone)(o-benzenedithiolate)(bdt);di-tert-butyl-1,2-dithiobenzoquinone; hexafluoro-1,2-dithiobenzoquinone;1,2-dithionaphthoquinone; 9,10-dithiophenanthroquinone;ethylenedithiolene (edt); maleonitriledithiolene (mnt);trifluoromethyldithiolene (tfd); carbomethoxydithiolene (cmt);trithionedithiolene (dmit); toluenedithiolate (tdt); dithiomanaldehyde(propenethionethiolate)(ptt); dithioacetylacetonate (SacSac);dijulolidinedithiolene; 2,3-piperazinedithiolate;di(4-aminophenyl)dithiolene; dimercaptoisotrithione (dmit);(4-octylphenyl)dithiolene; benzenetetrathiol; tetrathiosquaric acid;trithiodeltic acid; pentathiocroconic acid; dithiocroconic acid;hexathiorhodizonic acid; dithiorhodizonic acid; ethylenetetrathiol;trans-butadienetetrathiolate; tetrathiooxalic acid; 1,2-indandithione;naphthothioquinone; acenapthenethioquinone; aceanthrenethioquinone; andindole-2,3-dithione (thioisatin).

S Valence Stabilizer #7: Examples of dithiomalonamides(dithiomalonodiamides), bis(dithiomalonamides), andpolydithiomalonamides (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: dithiomalonamide,N-phenyldithiomalonamide, N-benzyldithiomalonamide,N-pentafluorophenyldithiomalonamide, N-cyclohexyldithiomalonamide,N-norbornyldithiomalonamide, N,N′-diphenyldithiomalonamide,N,N′-dibenzyldithiomalonamide, N,N′-dipentafluorophenyldithiomalonamide,N,N′-dicyclohexyldithiomalonamide, and N,N′-norbornyldithiomalonamide.

S Valence Stabilizer #8: Examples of 2-thioacylthioacetamides,bis(2-thioacylthioacetamides), and poly(2-thioacylthioacetamides) (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-thioacetothioacetamide,N-phenyl-2-thioacetothioacetamide,N-pentafluorophenyl-2-thioacetothioacetamide,N-benzyl-2-thioacetothioacetamide,N-cyclohexyl-2-thioacetothioacetamide,N-norbornyl-2-thioacetothioacetamide, N-phenyl-2-thiobenzothioacetamide,N-pentafluorophenyl-2-pentafluorothiobenzothioacetamide, andN-cyclohexyl-2-thiocyclohexothioacetamide.

S Valence Stabilizer #9: Examples of dithioacyl sulfides, bis(dithioacylsulfides), and poly(dithioacyl sulfides), (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithioacetyl sulfide; dithiopropanoyl sulfide; dithiobenzoylsulfide; and dithiopentafluorobenzoyl sulfide.

S Valence Stabilizer #10: Examples of trithiodicarbonic diamides,bis(trithiodicarbonic diamides), and poly(trithiodicarbonic diamides)(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: trithiodicarbonic diamide;N-phenyltrithiodicarbonic diamide; N-pentafluorophenyltrithiodicarbonicdiamide; N-benzyltrithiodicarbonic diamide;N-cyclohexyltrithiodicarbonic diamide; N-norbornyltrithiodicarbonicdiamide; N,N′-diphenyltrithiodicarbonic diamide;N,N′-dipentafluorophenyltrithiodicarbonic diamide;N,N′-dibenzyltrithiodicarbonic diamide;N,N′-dicyclohexyltrithiodicarbonic diamide; andN,N′-dinorbornyltrithiodicarbonic diamide.

S Valence Stabilizer #11: Examples of pentathio-, tetrathio-, ortrithiodicarbonic acids, bis(pentathio-, tetrathio-, ortrithiodicarbonic acids), poly(pentathio-, tetrathio-, ortrithiodicarbonic acids), and derivatives thereof (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: pentathiodicarbonic acid, tetrathiodicarbonic acid,trithiodicarbonic acid, O-phenyltrithiodicarbonic acid,O-benzyltrithiodicarbonic acid, O-cyclohexyltrithiodicarbonic acid,O-norbornyltrithiodicarbonic acid, O,O′-diphenyltrithiodicarbonic acid,O,O′-dibenzyltrithiodicarbonic acid, O,O′-dicyclohexyltrithiodicarbonicacid, and O,O′-dinorbornyltrithiodicarbonic acid.

S Valence Stabilizer #12: Examples of dithiohypophosphoric acids,bis(dithiohypophosphoric acids), poly(dithiohypophosphoric acids), andderivatives thereof (S—S Bidentates, S—S Tridentates, S—S Tetradentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: dithiohypophosphoric acid,methyldithiohypophosphoric acid, isopropyldithiohypophosphoric acid,tert-butyldithiohypophosphoric acid, phenyldithiohypophosphoric acid,pentafluorophenyldithiohypophosphoric acid, benzyldithiohypophosphoricacid, cyclohexyldithiohypophosphoric acid, norbornyldithiohypophosphoricacid, dimethyldithiohypophosphoric acid,diisopropyldiothiohypophosphoric acid, di-tert-butyldithiohypophosphoricacid, diphenyldithiohypophosphoric acid,di-pentafluorophenyldithiohypophosphoric acid,dibenzyldithiohypophosphoric acid, dicyclohexyldithiohypophosphoricacid, and dinorbornyldithiohypophosphoric acid.

S Valence Stabilizer #13: Examples of dithiohypophosphoramides,bis(dithiohypophosphoramides), and poly(dithiohypophosphoramides) (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiohypophosphoramide,N-methyldithiohypophosphoramide, N-isopropyldithiohypophosphoramide,N-tert-butyldithiohypophosphoramide, N-phenyldithiohypophosphoramide,N-pentafluorophenyldithiohypophosphoramide,N-benzyldithiohypophosphoramide, N-cyclohexyldithiohypophosphoramide,N-norbornyldithiohypophosphoramide,N,N′″-dimethyldithiohypophosphoramide,N,N′″-diisopropyldithiohypophosphoramide,N,N′″-di-tert-butyldithiohypophosphoramide,N,N′″-diphenyldithiohypophosphoramide,N,N′″-di-pentafluorophenyldithiohypophosphoramide,N,N′″-dibenzyldithiohypophosphoramide,N,N′″-dicyclohexyldithiohypophosphoramide, andN,N′″-dinorbornyldithiohypophosphoramide.

S Valence Stabilizer #14: Examples of dithioimidodiphosphoric acids,dithiohydrazidodiphosphoric acids, bis(dithioimidodiphosphoric acids),bis(dithiohydrazidodiphosphoric acids), poly(dithioimidodiphosphoricacids), poly(dithiohydrazidodiphosphoric acids), and derivatives thereof(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithioimidodiphosphoric acid,methyldithioimidodiphosphoric acid, isopropyldithioimidodiphosphoricacid, tert-butyldithioimidodiphosphoric acid,phenyldithioimidodiphosphoric acid,pentafluorophenyldithioimidodiphosphoric acid,benzyldithioimidodiphosphoric acid, cyclohexyldithioimidodiphosphoricacid, norbornyldithioimidodiphosphoric acid,dimethyldithioimidodiphosphoric acid,diisopropyldiothioimidodiphosphoric acid,di-tert-butyldithioimidodiphosphoric acid,diphenyldithioimidodiphosphoric acid,di-pentafluorophenyldithioimidodiphosphoric acid,dibenzyldithioimidodiphosphoric acid,dicyclohexyldithioimidodiphosphoric acid, anddinorbornyldithioimidodiphosphoric acid.

S Valence Stabilizer #15: Examples of dithioimidodiphosphoramides,dithiohydrazidodiphosphoramides, bis(dithioimidodiphosphoramides),bis(dithiohydrazidodiphosphoramides), poly(dithioimidodiphosphoramides),and poly(dithiohydrazidodiphosphoramides) (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithioimidodiphosphoramide, N-methyldithioimidodiphosphoramide,N-isopropyldithioimidodiphosphoramide,N-tert-butyldithioimidodiphosphoramide,N-phenyldithioimidodiphosphoramide,N-pentafluorophenyldithioimidodiphosphoramide,N-benzyldithioimidodiphosphoramide,N-cyclohexyldithioimidodiphosphoramide,N-norbornyldithioimidodiphosphoramide,N,N′″-dimethyldithioimidodiphosphoramide,N,N′″-diisopropyldithioimidodiphosphoramide,N,N′″-di-tert-butyldithioimidodiphosphoramide,N,N′″-diphenyldithioimidodiphosphoramide,N,N′″-di-pentafluorophenyldithioimidodiphosphoramide,N,N′″-dibenzyldithioimidodiphosphoramide,N,N′″-dicyclohexyldithioimidodiphosphoramide, andN,N′″-dinorbornyldithioimidodiphosphoramide.

S Valence Stabilizer #16: Examples of dithiodiphosphoramides,bis(dithiodiphosphoramides), and poly(dithiodiphosphoramides) (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiodiphosphoramide,N-methyldithiodiphosphoramide, N-isopropyldithiodiphosphoramide,N-tert-butyldithiodiphosphoramide, N-phenyldithiodiphosphoramide,N-pentafluorophenyldithiodiphosphoramide, N-benzyldithiodiphosphoramide,N-cyclohexyldithiodiphosphoramide, N-norbornyldithiodiphosphoramide,N,N′″-dimethyldithiodiphosphoramide,N,N′″-diisopropyldithiodiphosphoramide,N,N′″-di-tert-butyldithiodiphosphoramide,N,N′″-diphenyldithiodiphosphoramide,N,N′″-di-pentafluorophenyldithiodiphosphoramide,N,N′″-dibenzyldithiodiphosphoramide,N,N′″-dicyclohexyldithiodiphosphoramide, andN,N′″-dinorbornyldithiodiphosphoramide.

S Valence Stabilizer #17: Examples of dithiodiphosphoric acids,bis(dithiodipbosphoric acids), poly(dithiodiphosphoric acids), andderivatives thereof (S—S Bidentates, S—S Tridentates, S—S Tetradentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: dithiodiphosphoric acid,methyldithiodiphosphoric acid, isopropyldithiodiphosphoric acid,tert-butyldithiodiphosphoric acid, phenyldithiodiphosphoric acid,pentafluorophenyldithiodiphosphoric acid, benzyldithiodiphosphoric acid,cyclohexyldithiodiphosphoric acid, norbornyldithiodiphosphoric acid,dimethyldithiodiphosphoric acid, diisopropyldiothiodiphosphoric acid,di-tert-butyldithiodiphosphoric acid, diphenyldithiodiphosphoric acid,di-pentafluorophenyldithiodiphosphoric acid, dibenzyldithiodiphosphoricacid, dicyclohexyldithiodiphosphoric acid, anddinorbornyldithiodiphosphoric acid.

S Valence Stabilizer #18: Examples of trithiophosphoric acids(phosphorotrithioic acids), bis(trithiophosphoric acids),poly(trithiophosphoric acids), and derivatives thereof (S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: trithiophosphoric acid, O-phenyltrithiophosphoric acid,O-benzyltrithiophosphoric acid, O-cyclohexyltrithiophosphoric acid,O-norbornyltrithiophosphoric acid, O,S-diphenyltrithiophosphoric acid,O,S-dibenzyltrithiophosphoric acid, O,S-dicyclohexyltrithiophosphoricacid, and O,S-dinorbornyltrithiophosphoric acid.

S Valence Stabilizer #19: Examples of dithiophosphoric acids(phosphorodithioic acids), bis(dithiophosphoric acids),poly(dithiophosphoric acids), and derivatives thereof (S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithiophosphoric acid, O-phenyldithiophosphoric acid,O-benzyldithiophosphoric acid, O-cyclohexyldithiophosphoric acid,O-norbornyldithiophosphoric acid, O,O-diphenyldithiophosphoric acid,O,O-dibenzyldithiophosphoric acid, O,O-dicyclohexyldithiophosphoricacid, and O,O-dinorbornyldithiophosphoric acid.

S Valence Stabilizer #20: Examples of tetrathiophosphoric acids(phosphorotetrathioic acids), bis(tetrathiophosphoric acids),poly(tetrathiophosphoric acids), and derivatives thereof (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetrathiophosphoric acid,S-phenyltetrathiophosphoric acid, S-benzyltetrathiophosphoric acid,S-cyclohexyltetrathiophosphoric acid, S-norbornyltetrathiophosphoricacid, S,S-diphenyltetrathiophosphoric acid,S,S-dibenzyltetrathiophosphoric acid,S,S-dicyclohexyltetrathiophosphoric acid, andS,S-dinorbornyltetrathiophosphoric acid.

S Valence Stabilizer #21: Examples of phosphoro(dithioperoxo)dithioicacids, bis[phosphoro(dithioperoxo)dithioic acids],poly[phosphoro(dithioperoxo)dithioic acids], and derivatives thereof(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphoro(dithioperoxo)dithioic acid,O-phenylphosphoro(dithioperoxo)dithioic acid,O-benzylphosphoro(dithioperoxo)dithioic acid,O-cyclohexylphosphoro(dithioperoxo)dithioic acid,O-norbornylphosphoro(dithioperoxo)dithioic acid,O,S-diphenylphosphoro(dithioperoxo)dithioic acid,O,S-dibenzylphosphoro(dithioperoxo)dithioic acid,O,S-dicyclohexylphosphoro(dithioperoxo)dithioic acid, andO,S-dinorbornylphosphoro(dithioperoxo)dithioic acid.

S Valence Stabilizer #22: Examples of phosphoro(dithioperoxo)thioicacids, bis[phosphoro(dithioperoxo)thioic acids],poly[phosphoro(dithioperoxo)thioic acids], and derivatives thereof (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphoro(dithioperoxo)thioic acid,O-phenylphosphoro(dithioperoxo)thioic acid,O-benzylphosphoro(dithioperoxo)thioic acid,O-cyclohexylphosphoro(dithioperoxo)thioic acid,O-norbornylphosphoro(dithioperoxo)thioic acid,O,S-diphenylphosphoro(dithioperoxo)thioic acid,O,S-dibenzylphosphoro(dithioperoxo)thioic acid,O,S-dicyclohexylphosphoro(dithioperoxo)thioic acid, andO,S-dinorbornylphosphoro(dithioperoxo)thioic acid.

S Valence Stabilizer #23: Examples of phosphoro(dithioperoxo)trithioicacids, bis[phosphoro(dithioperoxo)trithioic acids],poly[phosphoro(dithioperoxo)trithioic acids], and derivatives thereof(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphoro(dithioperoxo)trithioic acid,O-phenylphosphoro(dithioperoxo)trithioic acid,O-benzylphosphoro(dithioperoxo)trithioic acid,O-cyclohexylphosphoro(dithioperoxo)trithioic acid,O-norbornylphosphoro(dithioperoxo)trithioic acid,O,S-diphenylphosphoro(dithioperoxo)trithioic acid,O,S-dibenzylphosphoro(dithioperoxo)trithioic acid,O,S-dicyclohexylphosphoro(dithioperoxo)trithioic acid, andO,S-dinorbornylphosphoro(dithioperoxo)trithioic acid.

S Valence Stabilizer #24: Examples of beta-mercaptothioketones,beta-mercaptothioaldehydes, bis(beta-mercaptothioketones),bis(beta-mercaptothioaldehydes), poly(beta-mercaptothioketones), andpoly(beta-mercaptothioaldehydes) (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:4-mercaptopentan-2-thione; 1,3-diphenyl-3-mercaptopropanethioaldehyde;1,3-dibenzyl-3-mercaptopropanethioaldehyde;1,3-dicyclohexyl-3-mercaptopropanethioaldehyde;1,3-dinorbornyl-3-mercaptopropanethioaldehyde;1,3-di(2-thienyl)-3-mercaptopropanethioaldehyde;1,3-di(2-furyl)-3-mercaptopropanethioaldehyde;o-mercaptothioacetophenone; 5-mercapto-1,4-dithionaphthoquinone;1-mercaptothioacridone; 1-mercaptodithioanthraquinone;1,8-dimercaptodithioanthraquinone; and beta-mercaptothiobenzophenone.

S Valence Stabilizer #25: Examples of N-(aminomethylthiol)thioureas[N-(aminomercaptomethyl)thioureas], bis[N-(aminomethylthiol)thioureas],and poly[N-(aminomethylthiol)thioureas] (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N′-(aminomercaptomethyl)thiourea;N,N″-dimethyl-N′-(aminomercaptomethyl)thiourea;N,N′-diethyl-N′-(aminomercaptomethyl)thiourea;N,N″-isopropyl-N′-(aminomercaptomethyl)thiourea;N,N″-diphenyl-N′-(aminomercaptomethyl)thiourea;N,N″-dibenzyl-N′-(aminonercaptomethyl)thiourea;N,N″-dicyclohexyl-N′-(aminomercaptomethyl)thiourea; andN,N″-dinorbornyl-N′-(aminomercaptomethyl)thiourea.

S Valence Stabilizer #26: Examples of dithiooxamides,bis(dithiooxamides), and poly(dithiooxamides) (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithiooxamide (rubeanic acid), N-methyldithiooxamide;N-ethyldithiooxamide; N-isopropyldithiooxamide; N-phenyldithiooxamide;N-benzyldithiooxamide; N-cyclohexyldithiooxamide;N-norbornyldithiooxamide; N,N′-dimethyldithiooxamide;N,N′-diethyldithiooxamide; N,N′-diisopropyldithiooxamide;N,N′-diphenyldithiooxamide; N,N′-dibenzyldithiooxamide;N,N′-dicyclohexyldithiooxamide; and N,N′-dinorbornyldithiooxamide.

S Valence Stabilizer #27: Examples of 1,1-dithiolates,bis(1,1-dithiolates), and poly(1,1-dithiolates) (S—S Bidentates and S—STetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:1,1-dicyano-2,2-ethylene dithiolate (i-mnt);1,1-dicarboalkoxy-2,2-ethylene dithiolate (DED);1,1-di(trifluoromethyl)-2,2-ethylene dithiolate;1,1-di(pentafluorophenyl)-2,2-ethylene dithiolate;1-pentamethylene-2,2-ethylene dithiolate; and 1-nitroethylenedithiolate.

S Valence Stabilizer #28: Examples of dithiomonocarboxylic acids, tri-and tetrathiodicarboxylic Acids, bis(dithiomonocarboxylic acids),bis(tri- and tetrathiodicarboxylic acids), poly(dithiomonocarboxylicacids), poly(tri- and tetrathiodicarboxylic acids), and derivativesthereof (S—S Bidentates and S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithioacetic acid; dithiopropionicacid; dithiobenzoic acid (dtb); dithiophenylacetic acid (dtpa);dithiocyclohexanoic acid; dithiofuroic acid; dithionaphthoic acid;phenyl dithioacetate; phenyl dithiopropionate; phenyl dithiobenzoate;phenyl dithiocyclohexanoate; phenyl dithiofuroate; phenyldithionaphthoate; tetrathiooxalic acid; tetrathiomalonic acid;tetrathiosuccinic acid; trithiooxalic acid; trithiomalonic acid;trithiosuccinic acid; diphenyl tetrathiooxalate; diphenyltetrathiomalonate; diphenyl tetrathiosuccinate; diphenyl trithiooxalate;diphenyl trithiomalonate; diphenyl trithiosuccinate; pyridinedithiocarboxylic acid; pyrrole dithiocarboxylic acid; thiophenedithiocarboxylic acid; dithionaphthoic acid; and tetrathiocamphonicacid.

S Valence Stabilizer #29: Examples of perthiomonocarboxylic acids,perthiodicarboxylic acids, bis(perthiomonocarboxylic acids),bis(perthiodicarboxylic acids), poly(perthiomonocarboxylic acids),poly(perthiodicarboxylic acids), and derivatives thereof (S—S Bidentatesand S—S Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:perthioacetic acid; perthiopropionic acid; perthiobenzoic acid;perthiophenylacetic acid; perthiocyclohexanoic acid; perthiofuroic acid;perthionaphthoic acid; phenyl perthioacetate; phenyl perthiopropionate;phenyl perthiobenzoate; phenyl perthiocyclohexanoate; phenylperthiofuroate; phenyl perthionaphthoate; perthiooxalic acid;perthiomalonic acid; perthiosuccinic acid; diphenyl perthiooxalate;diphenyl perthiomalonate; diphenyl perthiosuccinate; dithiole-3-thione(dithione-3-thione); and benzodithiole-3-thione(benzodithione-3-thione).

S Valence Stabilizer #30: Examples of dithiocarbonates,trithiocarbonates, perthiocarbonates, bis(dithiocarbonates),bis(trithiocarbonates), and bis(perthiocarbonates) (S—S Bidentates andS—S Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:S,S-diethyldithiocarbonate; S,S-diisopropyldithiocarbonate;S,S-diphenyldithiocarbonate; S,S-dibenzyldithiocarbonate;S,S-dicyclohexyldithiocarbonate; S,S-dinorbornyldithiocarbonate;diethyltrithiocarbonate; diisopropyltrithiocarbonate;diphenyltrithiocarbonate; dibenzyltrithiocarbonate;dicyclohexyltrithiocarbonate; and dinorbornyltrithiocarbonate.

S Valence Stabilizer #31: Examples of dithiocarbamates,bis(dithiocarbamates), and poly(dithiocarbamates) (includingN-hydroxydithiocarbamates and N-mercaptodithiocarbamates) (S—SBidentates, S—S Tridentates, and S—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dimethyldithiocarbamate (dmdtc);di(trifluorodimethyl)dithiocarbamate; diethyldithiocarbamate (dedtc);dipropyldithiocarbamate; diisopropyldithiocarbamate;dibutyldithiocarbamate; ditertbutyldithiocarbamate;dicyanamidodithiocarbamate; azidothioformates; diphenyldithiocarbamate;di(pentafluorophenyl)dithiocarbamate; dibenzyldithiocarbamate;dinaphthyldithiocarbamate; dicyclohexyldithiocarbamate;dinorbornyldithiocarbamate; diadamantyldithiocarbamate;pyrrolidinodithiocarbamate (pyrdtc); piperidinodithiocarbamate (pipdtc);morpholinodithiocarbamate (mordtc); thiamorpholinodithiocarbamate;3-pyrrolinodithiocarbamate; pyrrolodithiocarbamate;oxazolodithiocarbamate; isoxazolodithiocarbamate;thiazolodithiocarbamate; isothiazolodithiocarbamate;indolodithiocarbamate; carbazolodithiocarbamate;pyrazolinodithiocarbamate; imidazolinodithiocarbamate;pyrazolodithiocarbamate; imidazolodithiocarbamate;indazolodithiocarbamate; and triazolodithiocarbamate.

S Valence Stabilizer #32: Examples of dithiocarbazates(dithiocarbazides), bis(dithiocarbazates), and poly(dithiocarbazates)(S—S Bidentates, S—S Tridentates, and S—S Tetradentates; or possibly N—SBidentates, N—S Tridentates, and N—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N,N′-dimethyldithiocarbazate;N,N′-di(trifluoromethyl)dithiocarbazate; N,N′-diethyldithiocarbazate;N,N′-diphenyldithiocarbazate; N,N′-dibenzyldithiocarbazate;N,N′-di(pentafluorophenyl)dithiocarbazate;N,N′-dicyclohexyldithiocarbazate; and N,N′-dinorbornyldithiocarbazate.

S Valence Stabilizer #33: Examples of thiocyanate ligands (Smonodentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: thiocyanate(—SCN).

O Valence Stabilizer #1: Examples of biurets (imidodicarbonic diamides),isobiurets, biureas, triurets, triureas, bis(biurets), bis(isobiurets),bis(biureas), poly(biurets), poly(isobiurets), and poly(biureas) (O—OBidentates, O—O Tridentates, O—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: biuret, isobiuret, biurea, triuret,triurea, nitrobiuret, dinitrobiuret, aminobiuret, diaminobiuret,oxybiuret, dioxybiuret, cyanobiuret, methylbiuret, ethylbiuret,isopropylbiuret, phenylbiuret, benzylbiuret, cyclohexylbiuret,norbornylbiuret, adamantylbiuret, dimethylbiuret, diethylbiuret,diisopropylbiuret, diphenylbiuret, dibenzylbiuret, dicyclohexylbiuret,dinorbornylbiuret, and diadamantylbiuret.

O Valence Stabilizer #2: Examples of acylureas, aroylureas,bis(acylureas), bis(aroylureas), poly(acylureas), and poly(aroylureas)(O—O Bidentates, O—O Tridentates, O—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: formylurea, acetylurea, benzoylurea,cyclohexoylurea, pentafluorobenzoylurea, N-methylacetylurea,N-phenylbenzoylurea, and N-cyclohexylcyclohexoylurea.

O Valence Stabilizer #3: Examples of imidodialdehydes,hydrazidodialdehydes (acyl hydrazides), bis(imidodialdehydes),bis(hydrazidodialdehydes), poly(imidodialdehydes), andpoly(hydrazidodialdehydes) (O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: diacetamide,dipropanamide, dibutanamide, dibenzamide, and dicyclohexamide.

O Valence Stabilizer #4: Examples of imidodicarbonic acids,hydrazidodicarbonic acids, bis(imidodicarbonic acids),bis(hydrazidodicarbonic acids), poly(imidodicarbonic acids),poly(hydrazidodicarbonic acids) and derivatives thereof (O—O Bidentates,O—O Tridentates, O—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: imidodicarbonic acid, hydrazidodicarbonic acid,O-phenylimidodicarbonic acid, O-benzylimidodicarbonic acid,O-cyclohexylimidodicarbonic acid, O-norbornylimidodicarbonic acid,O,O′-diphenylimidodicarbonic acid, O,O′-dibenzylimidodicarbonic acid,O,O′-dicyclohexylimidodicarbonic acid, andO,O′-dinorbornylimidodicarbonic acid.

O Valence Stabilizer #5: Examples of imidodisulfamic acid,imidodisulfuric acid, bis(imidodisulfamic acid), bis(imidodisulfuricacid), poly(imidodisulfamic acid), and poly(imidodisulfuric acid) andderivatives thereof (O—O Bidentates, O—O Tridentates, O—O Tetradentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: imidodisulfamic acid,imidodisulfuric acid, N-phenylimidodisulfamic acid,N-benzylimidodisulfamic acid, N-cyclohexylimidodisulfamic acid,N-norbornylimidodisulfamic acid, N,N′-diphenylimidodisulfamic acid,N,N′-dibenzylimidodisulfamic acid, N,N′-dicyclohexylimidodisulfamicacid, and N,N′-norbornylimidodisulfamic acid.

O Valence Stabilizer #6: Examples of 1,3-diketones (beta-diketonates),1,3,5-triketones, bis(1,3-diketones), and poly(l,3-diketones), all witha molecular weight greater than 125 (O—O Bidentates, O—O Tridentates,O—O Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:hexafluoropentanedione; dibenzoylmethane(1,3-diphenyl-1,3-propanedione); benzoylpinacolone;dicyclohexoylmethane; diphenylpentanetrionate; dibenzoylacetone;benzoylacetylacetone; dibenzoylacetylacetone; tetramethylnonanetrionate;hexafluoroheptanetrionate; trifluoroheptanetrionate;trifluoroacetylcamphor (facam); and 1,3-indandione.

O Valence Stabilizer #7: Examples of 1,2-diketones (alpha-diketonates),1,2,3-triketones, tropolonates, o-quinones, bis(1,2-diketones), andpoly(1,2-diketones), all with a molecular weight greater than 100 (O—OBidentates, O—O Tridentates, O—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: tropolone; 1,2-benzoquinone(o-quinone); di-tert-butyl-1,2-benzoquinone;hexafluoro-1,2-benzoquinone; 1,2-naphthoquinone; 9,10-phenanthroquinone;and 1,2-indandione.

O Valence Stabilizer #8: Examples of malonamides (malonodiamides),bis(malonamides), and polymalonamides (O—O Bidentates, O—O Tridentates,O—O Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:malonamide, N-phenylmalonamide, N-benzylmalonamide,N-pentafluorophenylmalonamide, N-cyclohexylmalonamide,N-norbornylmalonamide, N,N′-diphenylmalonamide, N,N′-dibenzylmalonamide,N,N′-dipentafluorophenylmalonamide, N,N′-dicyclohexylmalonamide, andN,N′-norbornylmalonamide.

O Valence Stabilizer #9: Examples of 2-acylacetamides,bis(2-acylacetamides), and poly(2-acylacetamides) (O—O Bidentates, O—OTridentates, O—O Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-acetoacetamide, N-phenyl-2-acetoacetamide,N-pentafluorophenyl-2-acetoacetamide, N-benzyl-2-acetoacetamide,N-cyclohexyl-2-acetoacetamide, N-norbornyl-2-acetoacetamide,N-phenyl-2-benzoacetamide,N-pentafluorophenyl-2-pentafluorobenzoacetamide, andN-cyclohexyl-2-cyclohexoacetamide.

O Valence Stabilizer #10: Examples of monothiodicarbonic diamides,bis(monothiodicarbonic diamides), and poly(monothiodicarbonic diamides)(O—O Bidentates, O—O Tridentates, O—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothiodicarbonic diamide;N-phenylmonothiodicarbonic diamide;N-pentafluorophenylmonothiodicarbonic diamide;N-benzylmonothiodicarbonic diamide; N-cyclohexylmonothiodicarbonicdiamide; N-norbornylmonothiodicarbonic diamide;N,N′-diphenylmonothiodicarbonic diamide;N,N′-dipentafluorophenylmonothiodicarbonic diamide;N,N′-dibenzylmonothiodicarbonic diamide;N,N′-dicyclohexylmonothiodicarbonic diamide; andN,N′-dinorbornylmonothiodicarbonic diamide.

O Valence Stabilizer #11: Examples of monothiodicarbonic acids,bis(monothiodicarbonic acids), poly(monothiodicarbonic acids), andderivatives thereof (O—O Bidentates, O—O Tridentates, O—O Tetradentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: monothiodicarbonic acid,O-phenylmonothiodicarbonic acid, O-benzylmonothiodicarbonic acid,O-cyclohexylmonothiodicarbonic acid, O-norbornylmonothiodicarbonic acid,O,O′-diphenylmonothiodicarbonic acid, O,O′-dibenzylmonothiodicarbonicacid, O,O′-dicyclohexylmonothiodicarbonic acid, andO,O′-dinorbornylmonothiodicarbonic acid.

O Valence Stabilizer #12: Examples of trithionic acid, bis(trithionicacid), poly(trithionic acid), and derivatives thereof (O—O Bidentates,O—O Tridentates, O—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diphenyl trithionate, dipentafluorodiphenyl trithionate,dicyclohexyl trithionate, and dinorbornyl trithionate.

O Valence Stabilizer #13: Examples of hypophosphoric acids,bis(hypophosphoric acids), and poly(hypophosphoric acids), andderivatives thereof ((O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: hypophosphoricacid, O-methylhypophosphoric acid, O-isopropylhypophosphoric acid,O-tert-butylhypophosphoric acid, O-phenylhypophosphoric acid,O-pentafluorophenylhypophosphoric acid, O-benzylhypophosphoric acid,O-cyclohexylhypophosphoric acid, O-norbornylhypophosphoric acid,O,O″-dimethylhypophosphoric acid, O,O″-diisopropylhypophosphoric acid,O,O″-di-tert-butylhypophosphoric acid, O,O″-diphenylhypophosphoric acid,O,O″-di-pentafluorophenylhypophosphoric acid,O,O″-dibenzylhypophosphoric acid, O,O″-dicyclohexylhypophosphoric acid,and O,O″-dinorbornylhypophosphoric acid.

O Valence Stabilizer #14: Examples of hypophosphoramides,bis(hypophosphoramides), and poly(hypophosphoramides) (O—O Bidentates,O—O Tridentates, O—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: hypophosphoramide, N-methylhypophosphoramide,N-isopropylhypophosphoramide, N-tert-butylhypophosphoramide,N-phenylhypophosphoramide, N-pentafluorophenylhypophosphoramide,N-benzylhypophosphoramide, N-cyclohexylhypophosphoramide,N-norbornylhypophosphoramide, N,N′″-dimethylhypophosphoramide,N,N′″-diisopropylhypophosphoramide,N,N′″-di-tert-butylhypophosphoramide, N,N′″-diphenylhypophosphoramide,N,N′″-di-pentafluorophenylhypophosphoramide,N,N′″-dibenzylhypophosphoramide, N,N′″-dicyclohexylhypophosphoramide,and N,N′″-dinorbornylhypophosphoramide.

O Valence Stabilizer #15: Examples of imidodiphosphoric acids,hydrazidodiphosphoric acids, bis(imidodiphosphoric acids),bis(hydrazidodiphosphoric acids), poly(imidodiphosphoric acids),poly(hydrazidodiphosphoric acids), and derivatives thereof (O—OBidentates, O—O Tridentates, O—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: imidodiphosphoric acid,methylimidodiphosphoric acid, isopropylimidodiphosphoric acid,tert-butylimidodiphosphoric acid, phenylimidodiphosphoric acid,pentafluorophenylimidodiphosphoric acid, benzylimidodiphosphoric acid,cyclohexylimidodiphosphoric acid, norbornylimidodiphosphoric acid,dimethylimidodiphosphoric acid, diisopropylimidodiphosphoric acid,di-tert-butylimidodiphosphoric acid, diphenylimidodiphosphoric acid,di-pentafluorophenylimidodiphosphoric acid, dibenzylimidodiphosphoricacid, dicyclohexylimidodiphosphoric acid, anddinorbornylimidodiphosphoric acid.

O Valence Stabilizer #16: Examples of imidodiphosphoramides,hydrazidodiphosphoramides, bis(imidodiphosphoramides),bis(hydrazidodiphosphoramides), poly(imidodiphosphoramides), andpoly(hydrazidodiphosphoramides) (O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:imidodiphosphoramide, N-methylimidodiphosphoramide,N-isopropylimidodiphosphoramide, N-tert-butylimidodiphosphoramide,N-phenylimidodiphosphoramide, N-pentafluorophenylimidodiphosphoramide,N-benzylimidodiphosphoramide, N-cyclohexylimidodiphosphoramide,N-norbornylimidodiphosphoramide, N,N′″-dimethylimidodiphosphoramide,N,N′″-diisopropylimidodiphosphoramide,N,N′″-di-tert-butylimidodiphosphoramide,N,N′″-diphenylimidodiphosphoramide,N,N′″-di-pentafluorophenylimidodiphosphoramide,N,N′″-dibenzylimidodiphosphoramide,N,N′″-dicyclohexylimidodiphosphoramide, andN,N′″-dinorbornylimidodiphosphoramide.

O Valence Stabilizer #17: Examples of diphosphoramides,bis(diphosphoramides), and poly(diphosphoramides) (O—O Bidentates, O—OTridentates, O—O Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diphosphoramide, N-methyldiphosphoramide,N-isopropyldiphosphoramide, N-tert-butyldiphosphoramide,N-phenyldiphosphoramide, N-pentafluorophenyldiphosphoramide,N-benzyldiphosphoramide, N-cyclohexyldiphosphoramide,N-norbornyldiphosphoramide, N,N′″-dimethyldiphosphoramide,N,N′″-diisopropyldiphosphoramide, N,N′″-di-tert-butyldiphosphoramide,N,N′″-diphenyldiphosphoramide,N,N′″-di-pentafluorophenyldiphosphoramide,N,N′″-dibenzyldiphosphoramide, N,N′″-dicyclohexyldiphosphoramide, andN,N′″-dinorbornyldiphosphoramide.

O Valence Stabilizer #18: Examples of beta-hydroxyketones,beta-hydroxyaldehydes, bis(beta-hydroxyketones),bis(beta-hydroxyaldehydes), poly(beta-hydroxyketones), andpoly(beta-hydroxyaldehydes) (O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:4-hydroxypentan-2-one; 1,3-diphenyl-3-hydroxypropanal;1,3-dibenzyl-3-hydroxypropanal; 1,3-dicyclohexyl-3-hydroxypropanal;1,3-dinorbornyl-3-hydroxypropanal; 1,3-di(2-thienyl)-3-hydroxypropanal;1,3-di(2-furyl)3-hydroxypropanal; o-hydroxyacetophenone; juglone;alizarin; 1-hydroxyanthraquinone; 1,8-hydroxyanthraquinone;1-hydroxyacridone; and beta-hydroxybenzophenone.

O Valence Stabilizer #19: Examples of oxamides, bis(oxamides), andpoly(oxamides) (O—O Bidentates, O—O Tridentates, O—O Tetradentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: oxamide, N-methyloxamide;N-ethyloxamide; N-isopropyloxamide; N-phenyloxamide; N-benzyloxamide;N-cyclohexyloxamide; N-norbornyloxamide; N,N′-dimethyloxamide;N,N′-diethyloxamide; N,N′-diisopropyloxamide; N,N′-diphenyloxamide;N,N′-dibenzyloxamide; N,N′-dicyclohexyloxamide; andN,N′-dinorbornyloxamide.

O Valence Stabilizer #20: Examples of squaric acids and derivativesthereof (O—O Bidentates) that meet the requirements for use as “wideband” valence stabilizers for Ce⁺⁴ include, but are not limited to:deltic acid; squaric acid; croconic acid; and rhodizonic acid.

O Valence Stabilizer #21: Examples of dicarboxylic acids,bis(dicarboxylic acids), poly(dicarboxylic acids), and derivativesthereof (O—O Bidentates and O—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: oxalic acid; malonic acid; succinicacid; diphenyl oxalate; diphenyl malonate; and diphenyl succinate.

O Valence Stabilizer #22: Examples of carbonates and bis(carbonates)(O—O Bidentates and O—O Tetradentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: carbonate; bicarbonate; O,O-diethylcarbonate;diisopropylcarbonate; diphenylcarbonate; dibenzylcarbonate;dicyclohexylcarbonate; and dinorbornylcarbonate.

O Valence Stabilizer #23: Examples of carbamates, bis(carbamates), andpoly(carbamates) (including N-hydroxycarbamates andN-mercaptocarbamates) (O—O Bidentates, O—O Tridentates, and O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: dimethylcarbamate(dmc); di(trifluorodimethyl)carbamate; ethyl carbamate; diethylcarbamate(dec); dipropylcarbamate; diisopropylcarbamate; dibutylcarbamate;ditertbutylcarbamate; dicyanamidocarbamate; diphenylcarbamate;di(pentafluorophenyl)carbamate; dibenzylcarbamate; dinaphthylcarbamate;dicyclohexylcarbamate; dinorbornylcarbamate; diadamantylcarbamate;pyrrolidinocarbamate (pyrc); piperidinocarbamate (pipc);morpholinocarbamate (morc); thiamorpholinocarbamate;3-pyrrolinocarbamate; pyrrolocarbamate; oxazolocarbamate;isoxazolocarbamate; thiazolocarbamate; isothiazolocarbamate;indolocarbamate; carbazolocarbamate; pyrazolinocarbamate;imidazolinocarbamate; pyrazolocarbamate; imidazolocarbamate;indazolocarbamate; and triazolocarbamate.

O Valence Stabilizer #24: Examples of carbimates, bis(carbimates), andpoly(carbimates) (O—O Bidentates, O—O Tridentates, and O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: methylcarbimate;trifluoromethylcarbimate; ethylcarbimate; propylcarbimate;isopropylcarbimate; butylcarbimate; tertbutylcarbimate; cyanocarbimate;cyanamidocarbimate; azidocarbimate; phenylcarbimate;pentafluorophenylcarbimate; benzylcarbimate; naphthylcarbimate;cyclohexylcarbimate; norbornylcarbimate; and adamantylcarbimate. [Note:carbimates tend to stabilize lower oxidation states in metal ions.]

O Valence Stabilizer #25: Examples of N-(aminomethylol)ureas[N-(aminohydroxymethyl)ureas], bis[N-(aminomethylol)ureas], andpoly[N-(aminomethylol)ureas](O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:N′-(aminohydroxymethyl)urea; N,N″-dimethyl-N′-(aminohydroxymethyl)urea;N,N′-diethyl-N′-(aminohydroxymethyl)urea;N,N″-isopropyl-N′-(aminohydroxymethyl)urea;N,N″-diphenyl-N′-(aminohydroxymethyl)urea;N,N″-dibenzyl-N′-(aminohydroxymethyl)urea;N,N″-dicyclohexyl-N′-(aminohydroxymethyl)urea; andN,N″-dinorbornyl-N′-(aminohydroxymethyl)urea.

O Valence Stabilizer #26: Examples of cyanate ligands (O monodentates)that meet the (—OCN).

N—S Valence Stabilizer #1: Examples of diformamidine disulfides(thioperoxydicarbonimidic diamides), thioperoxytricarbonimidic diamides,thioperoxytetracarbonimidic diamides, bis(diformamidine disulfides), andpoly(diformamidine disulfides) (N—S bidentates, N—N—S tridentates, orN—S tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diformamidine disulfide; methyldiformamidine disulfide;ethyldiformamidine disulfide; isopropyldiformamidine disulfide;butyldiformamidine disulfide; benzyldiformamidine disulfide;phenyldiformamidine disulfide; tolyldiformamidine disulfide;naphthyldiformamidine disulfide; cyclohexyldiformamidine disulfide;norbornyldiformamidine disulfide; adamantyldiformamidine disulfide;dimethyldiformamidine disulfide; diethyldiformamidine disulfide;diisopropyldiformamidine disulfide; dibutyldiformamidine disulfide;dibenzyldiformamidine disulfide; diphenyldiformamidine disulfide;ditolyldiformamidine disulfide; dinaphthyldiformamidine disulfide;dicyclohexyldiformamidine disulfide; dinorbornyldiformamidine disulfide;diadamantyldiformamidine disulfide; 2-S-amidinodisulfidothiazole;2-S-amidinodisulfidooxazole; 2-S-amidinodisulfidoimidazole;3-S-amidinodisulfidopyrazole; 3-S-amidinodisulfido-1,2,4-triazole; and5-S-amidinodisulfidotetrazole.

N—S Valence Stabilizer #2: Examples of S-amidinodithiocarbamates,bis(S-amidinodithiocarbamates), and poly(S-amidinodithiocarbamates) (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: S-amidinodithiocarbamate; N-methyl-S-amidinodithiocarbamate;N-ethyl-S-amidinodithiocarbamate; N-isopropyl-S-amidinodithiocarbamate;N-butyl-S-amidinodithiocarbamate; N-benzyl-S-amidinodithiocarbamate;N-phenyl-S-amidinodithiocarbamate; N-tolyl-S-amidinodithiocarbamate;N-naphthyl-S-amidinodithiocarbamate;N-cyclohexyl-S-amidinodithiocarbamate;N-norbornyl-S-amidinodithiocarbamate;N-adamantyl-S-amidinodithiocarbamate;N,N′-dimethyl-S-amidinodithiocarbamate;N,N′-diethyl-S-amidinodithiocarbamate;N,N′-diisopropyl-S-amidinodithiocarbamate;N,N′-dibutyl-S-amidinodithiocarbamate;N,N′-dibenzyl-S-amidinodithiocarbamate;N,N′-diphenyl-S-amidinodithiocarbamate;N,N′-ditolyl-S-amidinodithiocarbamate;N,N′-dinaphthyl-S-amidinodithiocarbamate;N,N′-dicyclohexyl-S-amidinodithiocarbamate;N,N′-dinorbornyl-S-amidinodithiocarbamate;N,N′-diadamantyl-S-amidinodithiocarbamate;ethylenebis(S-amidinodithiocarbamate);propylenebis(S-amidinodithiocarbamate);phenylenebis(S-amidinodithiocarbamate);piperazinebis(S-amidinodithiocarbamate);oxalylbis(S-amidinodithiocarbamate);malonylbis(S-amidinodithiocarbamate);succinylbis(S-amidinodithiocarbamate);phthalylbis(S-amidinodithiocarbamate); 2-S-dithiocarbamatothiazole;2-S-dithiocarbamatooxazole; 2-S-dithiocarbamatoimidazole;3-S-dithiocarbamatopyrazole; 3-S-dithiocarbamato-1,2,4-triazole; and5-S-dithiocarbamatotetrazole.

N—S Valence Stabilizer #3: Examples of O-amidinothiocarbamates,bis(O-amidinothiocarbamates), and poly(O-amidinothiocarbamates) (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: O-amidinothiocarbamate; N-methyl-O-amidinothiocarbamate;N-ethyl-O-amidinothiocarbamate; N-isopropyl-O-amidinothiocarbamate;N-butyl-O-amidinothiocarbamate; N-benzyl-O-amidinothiocarbamate;N-phenyl-O-amidinothiocarbamate; N-tolyl-O-amidinothiocarbamate;N-naphthyl-O-amidinothiocarbamate; N-cyclohexyl-O-amidinothiocarbamate;N-norbornyl-O-amidinothiocarbamate; N-adamantyl-O-amidinothiocarbamate;N,N′-dimethyl-O-amidinothiocarbamate;N,N′-diethyl-O-amidinothiocarbamate;N,N′-diisopropyl-O-amidinothiocarbamate;N,N′-dibutyl-O-amidinothiocarbamate;N,N′-dibenzyl-O-amidinothiocarbamate;N,N′-diphenyl-O-amidinothiocarbamate;N,N′-ditolyl-O-amidinothiocarbamate;N,N′-dinaphthyl-O-amidinothiocarbamate;N,N′-dicyclohexyl-O-amidinothiocarbamate;N,N′-dinorbornyl-O-amidinothiocarbamate;N,N′-diadamantyl-O-amidinothiocarbamate;ethylenebis(O-amidinothiocarbamate);propylenebis(O-amidinothiocarbamate);phenylenebis(O-amidinothiocarbamate);piperazinebis(O-amidinothiocarbamate);oxalylbis(O-amidinothiocarbamate); malonylbis(O-amidinothiocarbamate);succinylbis(O-amidinothiocarbamate);phthalylbis(O-amidinothiocarbamate); 2-O-monothiocarbamatothiazole;2-O-monothiocarbamatooxazole; 2-O-monothiocarbamatoimidazole;3-O-monothiocarbamatopyrazole; 3-O-monothiocarbamato-1,2,4-triazole; and5-O-monothiocarbamatotetrazole.

N—S Valence Stabilizer #4: Examples of S-amidinoperoxythiocarbamates,bis(S-amidinoperoxythiocarbamates), andpoly(S-amidinoperoxythiocarbamates) (N—S Bidentates and N—STetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:S-amidinoperoxythiocarbamate; N-methyl-S-amidinoperoxythiocarbamate;N-ethyl-S-amidinoperoxythiocarbamate;N-isopropyl-S-amidinoperoxythiocarbamate;N-butyl-S-amidinoperoxythiocarbamate;N-benzyl-S-amidinoperoxythiocarbamate;N-phenyl-S-amidinoperoxythiocarbamate;N-tolyl-S-amidinoperoxythiocarbamate;N-naphthyl-S-amidinoperoxythiocarbamate;N-cyclohexyl-S-amidinoperoxythiocarbamate;N-norbornyl-S-amidinoperoxythiocarbamate;N-adamantyl-S-amidinoperoxythiocarbamate;N,N′-dimethyl-S-amidinoperoxythiocarbamate;N,N′-diethyl-S-amidinoperoxythiocarbamate;N,N′-diisopropyl-S-amidinoperoxythiocarbamate;N,N′-dibutyl-S-amidinoperoxythiocarbamate;N,N′-dibenzyl-S-amidinoperoxythiocarbamate;N,N′-diphenyl-S-amidinoperoxythiocarbamate;N,N′-ditolyl-S-amidinoperoxythiocarbamate;N,N′-dinaphthyl-S-amidinoperoxythiocarbamate;N,N′-dicyclohexyl-S-amidinoperoxythiocarbamate;N,N′-dinorbornyl-S-amidinoperoxythiocarbamate;N,N′-diadamantyl-S-amidinoperoxythiocarbamate;ethylenebis(S-amidinoperoxythiocarbamate);propylenebis(S-amidinoperoxythiocarbamate);phenylenebis(S-amidinoperoxythiocarbamate);piperazinebis(S-amidinoperoxythiocarbamate);oxalylbis(S-amidinoperoxythiocarbamate);malonylbis(S-amidinoperoxythiocarbamate);succinylbis(S-amidinoperoxythiocarbamate); andphthalylbis(S-amidinoperoxythiocarbamate).

N—S Valence Stabilizer #5: Examples of phosphorimidothioic acid;phosphorimidodithioic acid; phosphorimidotrithioic acid;bis(phosphorimidothioic acid); bis(phosphorimidodithioic acid);bis(phosphorimidotrithioic acid); poly(phosphorimidothioic acid);poly(phosphorimidodithioic acid); poly(phosphorimidotrithioic acid); andderivatives thereof (N—S Bidentates and N—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphorimidothioic acid;phosphorimidodithioic acid; phosphorimidotrithioic acid;O-phenylphosphorimidothioic acid; O-benzylphosphorimidothioic acid;O-cyclohexylphosphorimidothioic acid; O-norbornylphosphorimidothioicacid; O,O′-diphenylphosphorimidothioic acid;O,O′-dibenzylphosphorimidothioic acid;O,O′-dicyclohexylphosphorimidothioic acid; andO,O′-dinorbornylphosphorimidothioic acid.

N—S Valence Stabilizer #6: Examples of phosphorothioic triamides,bis(phosphorothioic triamides), and poly(phosphorothioic triamides) (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphorothioic triamide; phosphorothioic trihydrazide;phosphoramidothioic dihydrazide; N-phenylphosphorothioic triamide;N-benzylphosphorothioic triamide; N-cyclohexylphosphorothioic triamide;N-norbornylphosphorothioic triamide; N,N′-diphenylphosphorothioictriamide; N,N′-dibenzylphosphorothioic triamide;N,N′-dicyclohexylphosphorothioic triamide; andN,N′-dinorbornylphosphorothioic triamide.

N—S Valence Stabilizer #7: Examples of phosphoramidotrithioic acid,phosphorodiamidodithioic acid, bis(phosphoramidotrithioic acid),bis(phosphorodiamidodithioic acid), poly(phosphoramidotrithioic acid),poly(phosphorodiamidodithioic acid), and derivatives thereof (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphoramidotrithioic acid, phosphorodiamidodithioic acid,S-phenylphosphoramidotrithioic acid, S-benzylphosphoramidotrithioicacid, S-cyclohexylphosphoramidotrithioic acid,S-norbornylphosphoramidotrithioic acid,S,S′-diphenylphosphoramidotrithioic acid,S,S′-dibenzylphosphoramidotrithioic acid,S,S′-dicyclohexylphosphoramidotrithioic acid, andS,S′-dinorbornylphosphoramidotrithioic acid.

N—S Valence Stabilizer #8: Examples of phosphoramidothioic acid,phosphoramidodithioic acid, phosphorodiamidothioic acid,bis(phospboramidothioic acid), bis(phosphoramidodithioic acid),bis(phosphorodiamidothioic acid), poly(phosphoramidothioic acid),poly(phosphoramidodithioic acid), and poly(phosphorodiamidothioic acid)(N—S Bidentates and N—S Tetradentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: phosphoramidothioic acid, phosphoramidodithioic acid,phosphorodiamidothioic acid, phosphorohydrazidothioic acid,phosphorohydrazidodithioic acid, phosphorodihydrazidothioic acid,phosphoramidohydrazidothioic acid, O-phenylphosphoramidothioic acid,O-benzylphosphoramidothioic acid, O-cyclohexylphosphoramidothioic acid,O-norbornylphosphoramidothioic acid, S-phenylphosphoramidodithioic acid,S-benzylphosphoramidodithioic acid, S-cyclohexylphosphoramidodithioicacid, and S-norbornylphosphoramidodithioic acid.

N—S Valence Stabilizer #9: Examples of N-thioacyl7-aminobenzylidenimines (N—S Bidentates or N—S Tetradentates) that meetthe requirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N-thioacetyl7-methylaminobenzylidenimine; N-thioacetyl 7-phenylaminobenzylidenimine;N-thiobenzoyl 7-methylaminobenzylidenimine; and N-thiobenzoyl7-phenylaminobenzylidenimine.

N—S Valence Stabilizer #10: Examples of thiohydroxamates(thiohydroxylamines), bis(thiohydroxamates), and poly(thiohydroxamates)(N—S Bidentates, N—S Tetradentates, and N—S Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: acetothiohydroxamic acid;propianothiohydroxamic acid; butyrothiohydroxamic acid;crotonothiohydroxamic acid; sorbothiohydroxamic acid;benzothiohydroxamic acid; toluicthiohydroxamic acid;salicylthiohydroxamic acid; phenylacetothiohydroxamic acid;anthranilthiohydroxamic acid; nicotinethiohydroxamic acid;picolinethiohydroxamic acid; cyclohexanethiohydroxamic acid; quinoline8-thiohydroxamic acid; cinnamylthiohydroxamic acid; oxaldithiohydroxamicacid; succinylbis-N-phenylthiohydroxamic acid;adipylbis-N-phenylthiohydroxamic acid; glyoxalthiohydroxamic acid;2-thiophenethiocarbohydroxamic acid; thenoylthiohydroxamic acid;N-phenylbenzothiohydroxamic acid; N-tolylbenzothiohydroxamic acid;N-phenylacetothiohydroxamic acid; N-phenyl-2-thenoylthiohydroxamic acid;and N-tolyl-2-thenoylthiohydroxamic acid.

N—S Valence Stabilizer #11: Examples of alpha- orortho-aminothiocarboxylic acids, and alpha- orortho-aminothiodicarboxylic acids, and derivatives thereof (N—SBidentates, N—S Tridentates, and N—S Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-pyridinethiocarboxylic acid(thiopicolinic acid); 2-pyrazinethiocarboxylic acid; o-aminothiobenzoicacid; o-aminothionaphthoic acid; and 3,6-diaminothiophthalic acid.

N—S Valence Stabilizer #12: Examples of thiosemicarbazones,bis(thiosemicarbazones), and poly(thiosemicarbazones) (N—S Bidentates,N—S Tetradentates, and N—S Hexadentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: acetaldehyde thiosemicarbazone; acetone thiosemicarbazone;pinacolone thiosemicarbazone; benzaldehyde thiosemicarbazone;naphthaldebyde thiosemicarbazone; norbornanone thiosemicarbazone;camphor thiosemicarbazone; nopinone thiosemicarbazone; 2-pyridinaldehydethiosemicarbazone; salicylaldehyde thiosemicarbazone; quinolinaldehydethiosemicarbazone; isatin dithiosemicarbazone; camphorquinonedithiosemicarbazone; camphorquinone dithiosemicarbazone; picolinaldehydethiosemicarbazone; dipyridyl glyoxal dithiosemicarbazone; di-2-pyridylketone thiosemicarbazone; methyl-2-pyridyl ketone thiosemicarbazone;glyoxal dithiosemicarbazone; acetophenone thiosemicarbazone; biacetylmonoxime thiosemicarbazone; acetamidobenzaldehyde thiosemicarbazone;thymolaldothiosemicarbazone; thiophene-2-aldehyde thiosemicarbazone;phthalaldehyde dithiosemicarbazone; phthalimide dithiosemicarbazone;furaldehyde thiosemicarbazone; naphthoquinone thiosemicarbazone;phenanthrequinone thiosemicarbazone; cyclohexanedionedithiosemicarbazone; ionone thiosemicarbazone; bisthiosemicarbazone ofdiethyl-3,4-dioxadioate; pyridoxal alkylthiosemicarbazones; benzylidenephenylthiosemicarbazones; lawsone thiosemicarbazone; and1-benzoin-4-phenylthiosemicarbazone (bps).

N—S Valence Stabilizer #13: Examples of thioacyl hydrazones,bis(thioacyl hydrazones), and poly(thioacyl hydrazones) (N—S Bidentates,N—S Tetradentates, and N—S Hexadentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: acetaldehyde N-thioformylhydrazone; acetaldehydeN-thiobenzoylhydrazone; acetone N-thioformylhydrazone; acetoneN-thiobenzoylhydrazone; pinacolone N-thioformylhydrazone; pinacoloneN-thiobenzoylhydrazone; benzaldehyde N-thioformylhydrazone; benzaldehydeN-thiobenzoylhydrazone; naphthaldehyde N-thioformylhydrazone;naphthaldehyde N-thiobenzoylhydrazone; norbornanoneN-thioformylhydrazone; norbornanone N-thiobenzoylhydrazone; camphorN-thioformylhydrazone; camphor N-thiobenzoylhydrazone; nopinoneN-thioformylhydrazone; nopinone N-thiobenzoylhydrazone;2-pyridinaldehyde N-thioformylhydrazone; 2-pyridinaldehydeN-thiobenzoylhydrazone; salicylaldehyde N-thioformylhydrazone;salicylaldehyde N-thiobenzoylhydrazone; quinolinaldehydeN-thioformylhydrazone; quinolinaldehyde N-thiobenzoylhydrazone;thiophene-2-aldehyde N-thioformylhydrazone; thiophene-2-aldehydeN-thiobenzoylhydrazone; naphthoquinone N-thioformylhydrazone;naphthoquinone N-thiobenzoylhydrazone; ionone N-thioformylhydrazone;ionone N-thiobenzoylhydrazone; benzaldehyde benzothiazolehydrazone;lawsone N-thioformylhydrazone; and lawsone N-thiobenzoylhydrazone.

N—S Valence Stabilizer #14: Examples of thiocarbazones(diazenecarbothioic hydrazides), bis(thiocarbazones), andpoly(thiocarbazones) (N—S Bidentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:diphenylthiocarbazone (dithizone); 2-phenylthiocarbazone;dinaphthylthiocarbazone; 2-naphthylthiocarbazone; and ambazone.

N—S Valence Stabilizer #15: Examples of azo compounds with thiol ormercapto or thiocarbonyl substitution at the ortho- (for aryl) or alpha-or beta- (for alkyl) positions, Bis[o-(HS-) or alpha- or beta-(HS-)azocompounds], or Poly[o-(HS-) or alpha- or beta-(HS-)azo compounds) (N—SBidentates, N—S Tridentates, N—S Tetradentates, or N—S Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-thiolazobenzene[1-(phenylazo)-2-thiophenol]; 2,2′-dithioazobenzene;(2-thiophene)azobenzene; 1-(4-nitrophenylazo)-2-thionaphthol;2-thiazolylazobenzene; and 2-benzothiazolylazobenzene.

N—S Valence Stabilizer #16: Examples of diazeneformothioamides,diazeneacetothioamides, bis(diazeneformothioamides),bis(diazeneacetothioamides), poly(diazeneformothioamides), andpoly(diazeneacetothioamides) (N—S Bidentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:diazeneformothioamide, diazeneacetothioamide,phenyldiazeneformothioamide, diphenyldiazeneformothioamide,phenyldiazeneacetothioamide, and diphenyldiazeneacetothioamide.

N—S Valence Stabilizer #17: Examples of diazenecarbothioic acids,diazenecarbodithioic acids, bis(diazenecarbothioic acids),bis(diazenecarbodithioic acids), poly(diazenecarbothioic acids),poly(diazenecarbodithioic acids) and derivatives thereof (N—SBidentates, N—S Tetradentates, N—S Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: diazeneformothioic acid,diazeneacetothioic acid, phenyldiazeneformothioic acid,diphenyldiazeneformothioic acid, phenyldiazeneacetothioic acid, anddiphenyldiazeneacetothioic acid.

N—S Valence Stabilizer #18: Examples of diazeneformothioaldehydes,diazeneacetothioaldehydes, bis(diazeneformothioaldehydes),bis(diazeneacetothioaldehydes), poly(diazeneformothioaldehydes), andpoly(diazeneacetothioaldehydes) (N—S Bidentates, N—S Tetradentates andN—S Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diazeneformothioaldehyde, diazeneacetothioaldehyde,phenyldiazeneformothioaldehyde, diphenyldiazeneformothioaldehyde,phenyldiazeneacetothioaldehyde, and diphenyldiazeneacetothioaldehyde.

N—S Valence Stabilizer #19: Examples of diazenediformothioamides,diazenediacetothioamides, bis(diazenediformothioamides),bis(diazenediacetothioamides), poly(diazenediformothioamides), andpoly(diazenediacetothioamides) (N—S Tridentates and N—S Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: diazenediformodithioamide,diazenediacetodithioamide, diphenydiazenediformodithioamide,tetraphenyldiazenediformodithioamide, diphenyldiazenediacetodithioamide,and tetraphenyldiazenediacetodithioamide.

N—S Valence Stabilizer #20: Examples of diazenedicarbothioic acids,diazenedicarbodithioic acids, bis(diazenedicarbothioic acids),bis(diazenedicarbodithioic acids), poly(diazenedicarbothioic acids),poly(diazenedicarbodithioic acids) and derivatives thereof (N—STridentates and N—S Hexadentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazenediformothioic acid, diazenediacetodithioic acid,phenyldiazenediformothioic acid, diphenyldiazenediformothioic acid,phenyldiazenediacetodithioic acid, and diphenyldiazenediacetodithioicacid.

N—S Valence Stabilizer #21: Examples of diazenediformothioaldehydes,diazenediacetothioaldehydes, bis(diazenediformothioaldehydes),bis(diazenediacetothioaldehydes), poly(diazenediformothioaldehydes), andpoly(diazenediacetothioaldehydes) (N—S Tridentates and N—S Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: diazenediformothioaldehyde,diazenediacetothioaldehyde, diphenyldiazenediformothioaldehyde, anddiphenyldiazenediacetothioaldehyde.

N—S Valence Stabilizer #22: Examples of ortho-thio (or -mercapto)substituted formazans, bis(o-thio or -mercapto substituted formazans),and poly(o-thio or -mercapto substituted formazans) (N—S Bidentates, N—STridentates, N—S Tetradentates, and N—S Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 1-(2-thiophenyl)-3,5-diphenylformazan;1-(2-methylmercaptophenyl)-3,5-diphenylformazan;1,5-bis(2-thiophenyl)-3-phenylformazan; and5-bis(2-methylmercaptophenyl)-3-phenylformazan.

N—S Valence Stabilizer #23: Examples of ortho-thio (or -mercapto)substituted azines (including ketazines), bis(o-thio or mercaptosubstituted azines), and poly(o-thio or mercapto substituted azines)(N—S Bidentates, N—S Tridentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:2-mercapto-1-benzalazine; 2-mercapto-1-naphthalazine; and2-mercapto-1-cyclohexanonazine.

N—S Valence Stabilizer #24: Examples of Schiff Bases with one Imine(C═N) Group and with ortho- or alpha- or beta-thio or mercapto orthiocarbonyl substitution (N—S Bidentates, N—S Tridentates, N—STetradentates, N—S Pentadentates, or N—S Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N-(Thiosalicylaldehydo)isopropylamine;N-(2-thiophenecarboxaldehydo)isopropylamine;N-(2-Acetylthiopheno)isopropylamine;N-(2-Thioacetophenono)isopropylamine;N-(Thiosalicylaldehydo)cyclohexylamine;N-(2-Thiophenecarboxaldehydo)cyclohexylamine;N-(2-Acetylthiopheno)cyclohexylamine;N-(2-Thioacetophenono)cyclohexylamine; N-(Thiosalicylaldehydo)aniline;N-(2-Thiophenecarboxaldehydo)aniline; N-(2-Acetylthiopheno)aniline;N-(2-Thioacetophenono)aniline; N-(Thiosalicylaldehydo)aminonorbornane;N-(2-Thiocarboxaldehydo)aminonorbornane;N-(2-Acetylthiopheno)aminonorbornane;N-(2-Thioacetophenono)aminonorbornane;4-aminobenzylidene-3-propyl-5-mercapto-1,2,4-triazole;4-aminocinnamalidene-3-propyl-5-mercapto-1,2,4-triazole (acpmt);4-aminosalicylidene-3-propyl-5-mercapto-1,2,4-triazole (aspmt);4-aminovanillidene-3-propyl-5-mercapto-1,2,4-triazole;4-aminodimethylaminobenzylidene-3-propyl-5-mercapto-1,2,4-triazole(adpmt); cinnamylideneaminophenylthiazole;N-(2-mercaptophenyl)salicylidenimine; 2-thiophenecarboxaldehydephenylhydrazone; 2-thiophenecarboxaldehyde 2-pyridyl hydrazone;2-mercaptobenzaldehyde phenylhydrazone; and 2-mercaptobenzaldehyde2-pyridyl hydrazone. Also includes Schiff Bases derived from thereaction of carbonyl compounds with dithiocarbazates, and hydrazoneswith ortho-S substitution.

N—S Valence Stabilizer #25: Examples of Schiff Bases with two Imine(C═N) Groups and with ortho- or alpha- or beta-thio or mercapto orthiocarbonyl substitution (N—S Tridentates, N—S Tetradentates, N—SPentadentates, or N—S Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N,N′-(2,5-Thiophenedicarboxaldehydo)diisopropylamine;N,N′-(2,5-Thiophenedicarboxaldehydo)dicyclohexylamine;N,N′-(2,5-Thiophenedicarboxaldehydo)dianiline;N,N′-(2,5-Thiophenedicarboxaldehydo)di-aminonorbornane;N,N′-(o-Thiophthalicdialdehydo)diisopropylamine;N,N′-(o-Thiophthalicdialdehydo)dicyclohexylamine;N,N′-(o-Thiophthalicdialdehydo)dianiline;N,N′-(o-Thiophthalicdialdehydo)di-aminonorbornane;N,N′-(o-Thioformylcamphoro)diisopropylamine;N,N′-(o-Thioformylcamphoro)dicyclohexylamine;N,N′-(o-Thioformylcamphoro)dianiline;N,N′-(o-Thioformylcamphoro)di-aminonorbornane;N,N′-(o-Thiodiacetylbenzeno)diisopropylamine;N,N′-(o-Thiodiacetylbenzeno)dicyclohexylamine;N,N′-(o-Thiodiacetylbenzeno)dianiline;N,N′-(o-Thiodiacetylbenzeno)di-aminonorbornane;N,N′-(3,6-Dithio-1,2-cyclohexanono)diisopropylamine;N,N′-(3,6-Dithio-1,2-cyclohexanono)dicyclohexylamine;N,N′-(3,6-Dithio-1,2-cyclohexanono)dianiline;N,N′-(3,6-Dithio-1,2-cyclohexanono)di-aminonorbornane;N,N′-(2,5-Diacetylthiopheno)diisopropylamine;N,N′-(2,5-Diacetylthiopheno)dicyclohexylamine;N,N′-(2,5-Diacetylthiopheno)dianiline;N,N′-(2,5-Diacetylthiopheno)di-aminonorbornane;N,N′-(Thiosalicylaldehydo)ethylenediamine;N,N′-(o-Thionaphthaldehydo)ethylenediamine;N,N′-(o-Thioacetophenono)ethylenediamine;N,N′-(Thiosalicylaldehydo)trimethylenediamine;N,N′-(o-Thionaphthaldehydo)trimethylenediamine;N,N′-(o-Thioacetophenono)trimethylenediamine;N,N′-(Thiosalicylaldehydo)cyclohexane-1,2-diamine;N,N′-(o-Thionaphthaldehydo)cyclohexane-1,2-diamine;N,N′-(o-Thioacetophenono)cyclohexane-1,2-diamine;N,N′-(Thiosalicylaldehydo)-1,2-diaminobenzene;N,N′-(o-Thionaphthaldehydo) 1,2-diaminobenzene; andN,N′-(o-Thioacetophenono)-1,2-diaminobenzene. Also includes Schiff Basesderived from the reaction of carbonyl compounds with dithiocarbazates,and hydrazones with ortho-S substitution.

N—S Valence Stabilizer #26: Examples of Schiff Bases with three Imine(C═N) Groups and with ortho- or alpha- or beta-thio or mercapto orthiocarbonyl substitution (N—S Tetradentates, N—S Pentadentates, or N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:N,N′,N″-(Thiosalicylaldehydo)tris(2-aminoethyl)amine;N,N′,N″-(o-Thionaphthaldehydo)tris(2-aminoethyl)amine; andN,N′,N″-(o-Thioacetophenono)tris(2-aminoethyl)amine. Also includesSchiff Bases derived from the reaction of carbonyl compounds withdithiocarbazates, and hydrazones with ortho-S substitution.

N—S Valence Stabilizer #27: Examples of thioalkyl amines (aminothiols oraminodisulfides) and thioalkyl imines (iminothiols or iminodisulfides)(N—S Bidentates, N—S Tridentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:2-mercapto-1-aminoethane; 2-methylmercapto-1-aminoethane;3-mercapto-1-aminopropane; 1-mercapto-2-amino-2-methylpropane;2-mercaptocyclohexylamine; 3-mercapto-2-aminonorbornane;1,3-dimercapto-2-aminopropane; 1,5-dimercapto-3-aminopentane;2,2′-diaminodiethyl sulfide; 3,3′-diaminodipropyl sulfide;2,2′-diaminodicyclohexyl sulfide; 1,6-dimercapto-3,4-diaminohexane;1,7-dimercapto-3,5-diaminoheptane; 1,6-diamino-3,4-dimercaptohexane;1,7-diamino-3,5-dimercaptoheptane; tri(mercaptomethyl)amine;tri(2-mercaptoethyl)amine; dithiooxamide (rubeanic acid);2,2′-diaminodiethyl disulfide; 3,3′-diaminodipropyl disulfide;2,2′-diaminodicyclohexyl disulfide; 3-amino-1,5-pentanedithiodialdehyde;3,4-diamino-1,6-hexanedithiodialdehyde;3,5-diamino-1,7-heptanedithiodialdehyde; iminobisacetic acid;iminobispropionic acid; and bis(hydroxyethyl)aminoalkyl sulfide.

N—S Valence Stabilizer #28: Examples of thioaryl amines and thioarylimines (N—S Bidentates, N—S Tridentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: 2-aminothiophenol(2-aminobenzenethiol); 2-aminothiobenzoic acid (thioanthranilic acid);2-aminothioanisole; 2-(methanamine)benzyl mercaptan[(2-aminomethyl)alpha-toluenethiol][(2-mercaptomethyl)-alpha-aminotoluene];1-amino-2-naphthalenethiol; 2-amino-1-naphthalenethiol;2-amino-1-(methyldisulfido)benzene;2,2′-di(aminomethyl)diphenylthioketone; di(2-amino)phenyl sulfide;di(2-amino)phenyl disulfide (di-ortho-aminophenyl disulfide (doapd);1,3-di(2-amino)phenyl-2-mercaptopropane;1,3-di(3-amino)phenyl-2-mercaptopropane;1,3-di(2-mercapto)phenyl-2-aminopropane;1,3-di(3-mercapto)phenyl-2-aminopropane; 2,2′-dimercaptoiminodibenzyl;2,2′-iminodibenzothioic acid; 2,2′-dimercaptoiminostilbene; andpoly(o-aminothiophenol).

N—S Valence Stabilizer #29: Examples of five-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional sulfur atom binding site not in a ring (N—S Bidentates, N—STridentates, N—S Tetradentates, or N—S Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-mercaptopyrrole;2-(methylthio)methylpyrrole; 2,5(thiomethyl)pyrrole;2,5-(methylthiomethyl)pyrrole; 2,6(methyldisulfidomethyl)pyrrole;imidazoline-2-thione (2-mercaptoimidazole); 2-mercaptothiazoline;2-mercaptobenzimidazole; 2-mercaptobenzothiazole; 2-mercaptobenzoxazole;2-thiohydantoin; di-2-pyridylthioglyoxal (2,2′-thiopyridil);bis((1-pyrazolyl)methane)sulfide; bis((1-pyrazolyl)methane)disulfide;bis(2-(1-pyrazolyl)ethane)sulfide; bis(2-(I-pyrazolyl)ethane)disulfide;bis(benzimidazolylmethane)sulfide; bis(benzimidazolylethane)sulfide;bis(benzimidazolylmethane)disulfide;bis(benzimidazolylethane)disulfide;tris(imidazolyl)methanethiol;tris(imidazolylmethane)methanethiol;N-thiomethyl-N,N-(benzimidazolylmethane)amine;N-(2-thioethyl)-N,N-(benzimidazolylmethane)amine;N,N′-di(benzimidazolylmethane)-1,3-diamino-2-mercaptopropane;N,N,N′,N′-tetrakis(benzimidazolylmethane)-1,3-diamino-2-mercaptopropane;bis(N,N-((4-imidazolyl)methane)-2-aminoethane)sulfide;bis(N,N-((4-imidazolyl)methane)-2-aminoethane)disulfide;2-aminobenzothiazole (abt); 2-phenylaminothiazole; thiobydantoin;thioxohydropyrazole; 2-mercaptobenzothiazole (mbt);2-mercapto-1,3,4-thiadiazole; 2,5-dimercapto-1,3,4-thiadiazole(bismuthiol); 2,5-bis(alkylthio 1,3,4-thiadiazole;2-amino-5-mercapto-1,3,4-thiadiazole (amt); 5-mercaptotetrazole;1-phenyl-5-mercaptotetrazole (pmt) (5-mptt); 5-mercaptotriazole;3-mercaptotriazole; (2-benzothiazolyl)thioacetic acid;(2-benzothiazolyl)thiopropionic acid; (alkylthio)benzotriazoles;(arylthio)benzotriazoles; 2-mercaptopyrimidine;bis(5-mercapto-1,2,4-triazol-3-yl);bis(5-mercapto-1,2,4-triazol-3-yl)alkanes; 2-aminothiazolidine;thiazolidine-2-thione; 2-mercaptothiazolidine;1-(2-mercaptoethyl)imidazoline; imidazolidine-2-thione;4,5-dihydroxyimidazolidine-2-thione; 4-amino-5-mercapto-1,2,4-triazole;(2-benzimidazolylthio)carboxylic acids; (2-benzoxazolylthio)carboxylicacids; (2-benzothiazolylthio)carboxylic acids;(2-benzimidazolylthio)hydroxyalkyl(aryl)s;(2-benzoxazolylthio)hydroxyalkyl(aryl)s;(2-benzothiazolylthio)hydroxyalkyl(aryl)s;2-(phenylmethylthio)benzothiazole;2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles;2-(hydrocarbyldithio)-5-mercapto-1,3,4-thiadiazoles;bis(dithiobisthiadiazole); benzothiazolethione;3-hydrazino-5-thio-1,2,4-triazole; imidazolidine-2,4-dithione;dimercaptobenzothiazole; 2-aminothiazole (atz); thiadiazole-2-thione;5-mercaptothiadiazole-2-thione; 1,1-thiocarbonyldiimidazole;phosphosphonomethylenethio-1,3-benzothiazole (pmtbt);4,5-dihydroxyimidazolidine-2-thione; imidazolidine-2-thione;1,1′-thiocarbonyldiimidazole; 2,2′-dithiobis(benzothiazole); and5,5′-dithiobis(tetrazole).

N—S Valence Stabilizer #30: Examples of six-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional sulfur atom binding site not in a ring (N—S Bidentates, N—STridentates, N—S Tetradentates, or N—S Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 4-aminomethyl-3-pyridinemethanethiol(including thiopyridoxamine); 2-mercaptopyridine;2-(methylthio)methylpyridine; 2-(2-(methylthio)ethyl)pyridine;2,6-(thiomethyl)pyridine; 2,6-(methylthiomethyl)pyridine;2,6-(methyldisulfidomethyl)pyridine; 2-mercaptopyrimidine;2-dithiomethylpyrimidine; 2-mercaptoquinoline; 8-mercaptoquinoline(thioxine); 8-methylthioquinoline; 2-mercaptoquinazoline; thiooroticacid (1,2,3,6-tetrahydro-2,6-dithiono-4-pyrimidinecarboxylic acid)(6-thiouracilcarboxylic acid); 1-methylpyrimidine-2-thione;2-thiouracil; 2,4-dithiouracil; 6-mercaptopurine;bis(N,N,N′,N′-tetra(2-(2-pyridyl)ethane)aminomethane)sulfide;bis(N,N,N′,N′-tetra(2-(2-pyridyl)ethane)aminomethane)disulfide;bis(N,N,N′,N′-tetra(2-(2-pyridyl)ethane)aminoethane)sulfide;bis(N,N,N′,N′-tetra(2-(2-pyridyl)ethane)aminoethane)disulfide;1,3,5-triazine-6-thione; 2-benzylmercapto-1,3,5-triazine; triazinedithiols [i.e., 6-(phenylamino)-1,3,5-triazine-2,4-dithiol (ptd);6-aniline-1,3,5-triazine-2,4-dithiol (atd); and2-(N,N-dialkylamino)-1,3,5-triazine-4,6-dithiol]; 2-thioquinazoline;2-thioquinazolin-4-one; thiomorpholin-3-thione;[2-(aminomethyl)thio]pyridine; 6-mercaptopurine; dithiouracil; and2,2′-dithiodipyridine (2,2′-dipyridyl disulfide).

N—S Valence Stabilizer #31: Examples of five-membered heterocyclic ringscontaining one or two sulfur atoms at least one additional nitrogen atombinding site not in a ring (N—S Bidentates, N—S Tridentates, N—STetradentates, or N—S Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-aminothiophene; 2,5-diaminothiophene; 2-aminomethylthiophene;2,5-di(aminomethyl)thiophene; 2-aminobenzothiophene; and2-iminothiolane.

N—S Valence Stabilizer #32: Examples of six-membered heterocyclic ringscontaining one or two sulfur atoms at least one additional nitrogen atombinding site not in a ring (N—S Bidentates, N—S Tridentates, N—STetradentates, or N—S Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-aminothiopyran; 2,6-diaminothiopyran; 2-aminomethylthiopyran;2,6-di(aminomethyl)thiopyran; and 2-aminobenzothiopyran.

N—S Valence Stabilizer #33: Examples of five-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional sulfur atom binding site in a separate ring (N—S Bidentates,N—S Tridentates, N—S Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-(2-thiophene)pyrrole; 2,5-di(2-thiophene)pyrrole;2-(2-thiopyran)pyrrole; 2,5-di(2-thiopyran)pyrrole;2,5-di(2-pyrrole)thiophene; 2,6-di(2-pyrrole)thiopyran; and3,5-bis(2-thienyl)-4-amino-1,2,4-triazole (2-tat).

N—S Valence Stabilizer #34: Examples of six-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional sulfur atom binding site in a separate ring (N—S Bidentates,N—S Tridentates, N—S Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-(2-thiadiazolyl)benzimidazole; 2-(2-thiophene)pyridine;2,6-di(2-thiophene)pyridine; 2-(2-thiopyran)pyridine;2,6-di(2-thiopyran)pyridine; 2,5-di(2-pyridyl)thiophene;2,6-di(2-pyridyl)thiopyran; and 2-(4-thiazolyl)benzimidazole.

N—S Valence Stabilizer #35: Examples of two-, three-, four-, six-,eight-, and ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of nitrogen(usually amine or imine groups) or sulfur (usually thiols, mercaptans,or thiocarbonyls) and are not contained in component heterocyclic rings(N—S Bidentates, N—S Tridentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: azathiacyclobutane([4]aneNS); azathiacyclopentane ([5]aneNS); azathiacyclohexane([6]aneNS); azathiacycloheptane ([7]aneNS); azathiacyclooctane([8]aneNS); azathiacyclobutene ([4]eneNS); azathiacyclopentene([5]eneNS); azathiacyclohexene ([6]eneNS); azathiacycloheptene([7]eneNS); azathiacyclooctene ([8]eneNS); azathiacyclobutadiene([4]dieneNS); azathiacyclopentadiene ([5]dieneNS); azathiacyclohexadiene([6]dieneN S); azathiacycloheptadiene ([7]dieneN S);azathiacyclooctadiene ([8]dieneNS); diazathiacyclohexane ([6]aneSN₂);diazathiacycloheptane ([7]aneSN₂); diazathiacyclooctane ([8]aneSN₂);diazathiacyclononane ([9]aneSN₂); diazathiacyclodecane ([10]aneSN₂);diazathiacycloundecane ([11]aneSN₂); diazathiacyclododecane([12]aneSN₂); diazathiacyclohexene ([6]eneSN₂); diazathiacycloheptene([7]eneSN₂); diazathiacyclooctene ([8]eneSN₂); diazathiacyclononene([9]eneSN₂); diazathiacyclodecene ([10]eneSN₂); diazathiacycloundecene([11]eneSN₂); diazathiacyclododecene ([12]eneSN₂);diazadithiacyclooctane ([8]aneS₂N₂); diazadithiacyclononane([9]aneS₂N₂); diazadithiacyclodecane ([10]aneS₂N₂);diazadithiacycloundecane ([11]aneS₂N₂); diazadithiacyclododecane([12]aneS₂N₂); diazadithiacyclotridecane ([13]aneS₂N₂);diazadithiacyclotetradecane ([14]aneS₂N₂); diazadithiacyclopentadecane([15]aneS₂N₂); diazadithiacyclohexadecane ([16]aneS₂N₂);diazadithiacycloheptadecane ([17]aneS₂N₂); diazadithiacyclooctadecane([18]aneS₂N₂); diazadithiacyclononadecane ([19]aneS₂N₂);diazadithiacycloeicosane ([20]aneS₂N₂); diazadithiacyclooctadiene([8]dieneS₂N₂); diazadithiacyclononadiene ([9]dieneS₂N₂);diazadithiacyclodecadiene ([10]dieneS₂N₂); diazadithiacycloundecadiene([11]dieneS₂N₂); diazadithiacyclododecadiene ([12]dieneS₂N₂);diazadithiacyclotridecadiene ([13]dieneS₂N₂);diazadithiacyclotetradecadiene ([14]dieneS₂N₂);diazadithiacyclopentadecadiene ([15]dieneS₂N₂);diazadithiacyclohexadecadiene ([16]dieneS₂N₂);diazadithiacycloheptadecadiene ([17]dieneS₂N₂);diazadithiacyclooctadecadiene ([18]dieneS₂N₂);diazadithiacyclononadecadiene ([19]dieneS₂N₂);diazadithiacycloeicosadiene ([20]dieneS₂N₂); andtetramethyldithiahexaazacyclobidecanehexaene (mtab).

N—S Valence Stabilizer #36: Examples of four-, six-, eight-, orten-membered macrocyclics, macrobicyclics, and macropolycyclics(including catapinands, cryptands, cyclidenes, and sepulchrates) whereinall binding sites are composed of nitrogen or sulfur and are containedin component heterocyclic rings (N—S Bidentates, N—S Tridentates, N—STetradentates, or N—S Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithiopyrandipyridines; dithiophenedipyrroles;trithiopyrantripyridines; trithiophenetripyrroles;tetrathiopyrantetrapyridines; and tetrathiophenetetrapyrroles.

N—S Valence Stabilizer #37: Examples of four-, six-, eight-, orten-membered macrocyclics, macrobicyclics, and macropolycyclics(including catapinands, cryptands, cyclidenes, and sepulchrates) whereinall binding sites are composed of nitrogen or sulfur and are containedin a combination of heterocyclic rings and amine, imine, thiol,mercapto, or thiocarbonyl groups (N—S Bidentates, N—S Tridentates, N—STetradentates, or N—S Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: azathiatetraphyrins; diazadithiatetraphyrins; azathiahexaphyrins;diazadithiahexaphyrins; and triazatrithiahexaphyrins.

N—O Valence Stabilizer #1: Examples of N-hydroxy(orN,N′-dihydroxy)amidines and N-hydroxy(or N,N′-dihydroxy)diamidines (N—Obidentates, N—O tridentates, or N—O tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N-hydroxy-N,N′-dimethylformamidine;N-hydroxy-N,N′-diethylformamidine;N-hydroxy-N,N′-diisopropylformamidine;N-hydroxy-N,N′-dibutylformamidine; N-hydroxy-N,N′-diphenylformamidine;N-hydroxy-N,N′-dibenzylformamidine;N-hydroxy-N,N′-dinaphthylformamidine;N-hydroxy-N,N′-dicyclohexylformamidine;N-hydroxy-N,N′-dinorbornylformamidine;N-hydroxy-N,N′-diadamantylformamidine;N-hydroxy-N,N′-dianthraquinonylformamidine;N-hydroxy-N,N′-dimethylacetamidine; N-hydroxy-N,N′-diethylacetamidine;N-hydroxy-N,N′-diisopropylacetamidine;N-hydroxy-N,N′-dibutylacetamidine; N-hydroxy-N,N′-diphenylacetamidine;N-hydroxy-N,N′-dibenzylacetamidine;N-hydroxy-N,N′-dinaphthylacetamidine;N-hydroxy-N,N′-dicyclohexylacetamidine;N-hydroxy-N,N′-dinorbornylacetamidine;N-hydroxy-N,N′-diadamantylacetamidine;N-hydroxy-N,N′-dimethylbenzamidine; N-hydroxy-N,N′-diethylbenzamidine;N-hydroxy-N,N′-diisopropylbenzamidine;N-hydroxy-N,N′-dibutylbenzamidine; N-hydroxy-N,N′-diphenylbenzamidine;N-hydroxy-N,N′-dibenzylbenzamidine;N-hydroxy-N,N′-dinaphthylbenzamidine;N-hydroxy-N,N′-dicyclohexylbenzamidine;N-hydroxy-N,N′-dinorbornylbenzamidine;N-hydroxy-N,N′-diadamantylbenzamidine;N-hydroxy-N,N′-dimethyltoluamidine; N-hydroxy-N,N′-diethyltoluamidine;N-hydroxy-N,N′-diisopropyltoluamidine;N-hydroxy-N,N′-dibutyltoluamidine; N-hydroxy-N,N′-diphenyltoluamidine;N-hydroxy-N,N′-dibenzyltoluamidine;N-hydroxy-N,N′-dinaphthyltoluamidine;N-hydroxy-N,N′-dicyclohexyltoluamidine;N-hydroxy-N,N′-dinorbornyltoluamidine;N-hydroxy-N,N′-diadamantyltoluamidine; N,N-dihydroxyoxalic diamidine;N,N′-dihydroxymalonic diamidine; N,N′-dihydroxysuccinic diamidine;N,N′-dihydroxyglutaric diamidine; N,N′-dihydroxyadipic diamidine;N,N′-dihydroxypimelic diamidine; N,N′-dihydroxysuberic diamidine;N,N′-dihydroxyphthalic diamidine; N,N′-dihydroxyterephthalic diamidine;N,N′-dihydroxyisophthalic diamidine; N,N′-dihydroxypiperazine diamidine.

N—O Valence Stabilizer #2: Examples of guanylureas, guanidinoureas,bis(guanylureas), bis(guanidinoureas), poly(guanylureas), andpoly(guanidinoureas) (N—O Bidentates and N—O Tetradentates) that meetthe requirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: guanylurea(amidinourea)(dicyandiamidine); guanidinourea; methylguanylurea;ethylguanylurea; isopropylguanylurea; butylguanylurea; benzylguanylurea;phenylguanylurea; tolylguanylurea; naphthylguanylurea;cyclohexylguanylurea; norbornylguanylurea; adamantylguanylurea;dimethylguanylurea; diethylguanylurea; diisopropylguanylurea;dibutylguanylurea; dibenzylguanylurea; diphenylguanylurea;ditolylguanylurea; dinaphthylguanylurea; dicyclohexylguanylurea;dinorbornylguanylurea; diadamantylguanylurea; ethylenebis(guanylurea);propylenebis(guanylurea); phenylenebis(guanylurea);piperazinebis(guanylurea); oxalylbis(guanylurea);malonylbis(guanylurea); succinylbis(guanylurea);phthalylbis(guanylurea); 2-ureidothiazole; 2-ureidooxazole;2-ureidoimidazole; 3-ureidopyrazole; 3-ureido-1,2,4-triazole; and5-ureidotetrazole.

N—O Valence Stabilizer #3: Examples of amidinoamides, guanidinoamides,bis(amidinoamides), bis(guanidinoamides), poly(amidinoamides), andpoly(guanidinoamides) (including both N-amidinoamides and2-amidinoacetamides) (N—O Bidentates, N—O Tridentates, and N—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: amidinoacetamide(1-acetylguanidine); guanidinoacetamide; amidinopropanamide;amidinobutanamide; amidinobenzamide; amidinotoluamide;amidinocyclohexamide; N-methylamidinoacetamide;N-ethylamidinopropanamide; N-propylamidinobutanamide;N-phenylamidinobenzamide; N-tolylamidinotoluamide;N-cyclohexylamidinocyclohexamide; bis(amidinooxamide);bis(amidinomalonamide); bis(amidinosuccinamide);bis(amidinophthalamide); 2-amidinoacetamide (malonamamidine);N-methyl-2-amidinoacetamide; N-ethyl-2-amidinoacetamide;N-phenyl-2-amidinoacetamide; N-benzyl-2-amidinoacetamide;N-cyclohexyl-2-amidinoacetamide; N,N′-dimethyl-2-amidinoacetamide;N,N′-diethyl-2-amidinoacetamide; N,N′-diphenyl-2-amidinoacetamide;N,N′-dibenzyl-2-amidinoacetamide; N,N′-dicyclohexyl-2-amidinoacetamide;2-N-acylaminothiazole; 2-N-acylaminooxazole; 2-N-acylaminoimidazole;3-N-acylaminopyrazole; 3-N-acylamino-1,2,4-triazole; and5-N-acylaminotetrazole.

N—O Valence Stabilizer #4: Examples of imidoylamides,bis(imidoylamides), and poly(imidoylamides) (N—O Bidentates, N—OTridentates, and N—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: acetimidoylacetamide; acetimidoylpropanamide; acetimidoylbutanamide;acetimidoylbenzamide; acetimidolytoluamide; acetimidoylcyclohexamide;propimidoylpropanamide; butimidoylbutanamide; benzimidoylbenzamide;ethylenebis(acetimidoylacetamide); propylenebis(acetimidoylacetamide);and phenylenebis(acetimidoylacetamide).

N—O Valence Stabilizer #5: Examples of O-amidinocarbamates,bis(O-amidinocarbamates), and poly(O-amidinocarbamates) (N—O Bidentatesand N—O Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:O-amidinocarbamate; N-methyl-O-amidinocarbamate;N-ethyl-O-amidinocarbamate; N-isopropyl-O-amidinocarbamate;N-butyl-O-amidinocarbamate; N-benzyl-O-amidinocarbamate;N-phenyl-O-amidinocarbamate; N-tolyl-O-amidinocarbamate;N-naphthyl-O-amidinocarbamate; N-cyclohexyl-O-amidinocarbamate;N-norbornyl-O-amidinocarbamate; N-adamantyl-O-amidinocarbamate;N,N′-dimethyl-O-amidinocarbamate; N,N′-diethyl-O-amidinocarbamate;N,N′-diisopropyl-O-amidinocarbamate; N,N′-dibutyl-O-amidinocarbamate;N,N′-dibenzyl-O-amidinocarbamate; N,N′-diphenyl-O-amidinocarbamate;N,N′-ditolyl-O-amidinocarbamate; N,N′-dinaphthyl-O-amidinocarbamate;N,N′-dicyclohexyl-O-amidinocarbamate;N,N′-dinorbornyl-O-amidinocarbamate;N,N′-diadamantyl-O-amidinocarbamate; ethylenebis(O-amidinocarbamate);propylenebis(O-amidinocarbamate); phenylenebis(O-amidinocarbamate);piperazinebis(O-amidinocarbamate); oxalylbis(O-amidinocarbamate);malonylbis(O-amidinocarbamate); succinylbis(O-amidinocarbamate);phthalylbis(O-amidinocarbamate); 2-O-carbamatothiazole;2-O-carbamatooxazole; 2-O-carbamatoimidazole; 3-O-carbamatopyrazole;3-O-carbamato-1,2,4-triazole; and 5-carbamatotetrazole.

N—O Valence Stabilizer #6: Examples of S-amidinothiocarbamates,bis(S-amidinothiocarbamates), and poly(S-amidinothiocarbamates) (N—OBidentates and N—O Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: S-amidinothiocarbamate; N-methyl-S-amidinothiocarbamate;N-ethyl-S-amidinothiocarbamate; N-isopropyl-S-amidinothiocarbamate;N-butyl-S-amidinothiocarbamate; N-benzyl-S-amidinothiocarbamate;N-phenyl-S-amidinothiocarbamate; N-tolyl-S-amidinothiocarbamate;N-naphthyl-S-amidinothiocarbamate; N-cyclohexyl-S-amidinothiocarbamate;N-norbornyl-S-amidinothiocarbamate; N-adamantyl-S-amidinothiocarbamate;N,N′-dimethyl-S-amidinothiocarbamate;N,N′-diethyl-S-amidinothiocarbamate;N,N′-diisopropyl-S-amidinothiocarbamate;N,N′-dibutyl-S-amidinothiocarbamate;N,N′-dibenzyl-S-amidinothiocarbamate;N,N′-diphenyl-S-amidinothiocarbamate;N,N′-ditolyl-S-amidinothiocarbamate;N,N′-dinaphthyl-S-amidinothiocarbamate;N,N′-dicyclohexyl-S-amidinothiocarbamate;N,N′-dinorbornyl-S-amidinothiocarbamate;N,N′-diadamantyl-S-amidinothiocarbamate;ethylenebis(S-amidinothiocarbamate);propylenebis(S-amidinothiocarbamate);phenylenebis(S-amidinothiocarbamate);piperazinebis(S-amidinothiocarbamate);oxalylbis(S-amidinothiocarbamate); malonylbis(S-amidinothiocarbamate);succinylbis(S-amidinothiocarbamate);phthalylbis(S-amidinothiocarbamate); 2-O-monothiocarbamatothiazole;2-O-monothiocarbamatooxazole; 2-O-monothiocarbamatoimidazole;3-O-monothiocarbamatopyrazole; 3-O-monothiocarbamato-1,2,4-triazole; and5-O-monothiocarbamatotetrazole.

N—O Valence Stabilizer #7: Examples of diimidosulfuric acid,bis(diimidosulfuric acid), and derivatives thereof (N—O Bidentates andN—O Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diimidosulfuric acid; O-phenyldiimidosulfuric acid;O-benzyldiimidosulfuric acid, O-cyclohexyldiimidosulfuric acid,O-norbornyldiimidosulfuric acid, O,O′-diphenyldiimidosulfuric acid;O,O′-dibenzyldiimidosulfuric acid, O,O′-dicyclohexyldiimidosulfuricacid, and O,O′-dinorbornyldiimidosulfuric acid.

N—O Valence Stabilizer #8: Examples of phosphorimidic acid,bis(phosphorimidic acid); and poly(phosphorimidic acid), and derivativesthereof (N—O Bidentates, N—O Tetradentates) that meet the requirementsfor use as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: phosphorimidic acid; O-phenylphosphorimidic acid;O-benzylphosphorimidic acid; O-cyclohexylphosphorimidic acid;O-norbornylphosphorimidic acid; O,O′-diphenylphosphorimidic acid;O,O′-dibenzylphosphorimidic acid; O,O′-dicyclohexylphosphorimidic acid;and O,O′-dinorbornylphosphorimidic acid.

N—O Valence Stabilizer #9: Examples of phosphoric triamides,bis(phosphoric triamides), and poly(phosphoric triamides) (N—OBidentates and N—O Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphoric triamide; phosphoramidic dihydrazide; N-phenylphosphorictriamide, N-benzylphosphoric triamide; N-cyclohexylphosphoric triamide;N-norbornylphosphoric triamide; N,N′-diphenylphosphoric triamide,N,N′-dibenzylphosphoric triamide; N,N′-dicyclohexylphosphoric triamide;and N,N′-dinorbornylphosphoric triamide.

N—O Valence Stabilizer #10: Examples of phosphoramidic acid,phosphorodiamidic acid, bis(phosphoramidic acid), bis(phosphorodiamidicacid), poly(phosphoramidic acid), poly(phosphorodiamidic acid), andderivatives thereof (N—O Bidentates and N—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphoramidic acid, phosphorodiamidicacid, phosphoramidohydrazidic acid; phosphorohydrazidic acid;phosphorodihydrazidic acid; O-phenylphosphoramidic acid;O-benzylphosphoramidic acid; O-cyclohexylphosphoramidic acid;O-norbornylphosphoramidic acid; O,O′-diphenylphosphoramidic acid;O,O′-dibenzylphosphoramidic acid; O,O′-dicyclohexylphosphoramidic acid;and O,O′-dinorbornylphosphoramidic acid.

N—O Valence Stabilizer #11: Examples of N-acyl 7-aminobenzylidenimines(N—O Bidentates or N—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N-acetyl 7-methylaminobenzylidenimine; N-acetyl7-phenylaminobenzylidenimine; N-benzoyl 7-methylaminobenzylidenimine;and N-benzoyl 7-phenylaminobenzylidenimine.

N—O Valence Stabilizer #12: Examples of oximes, dioximes, andpoly(oximes) (N—O Bidentates, N—O Tridentates, and N—O Tetradentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: acetaldoxime (Hado); acetoxime(acetone oxime)(Hato); butanone oxime; pentanone oxime; hexanone oxime;pinacolone oxime; heptanone oxime; octanone oxime; cyclopentanone oxime;cyclohexanone oxime; cycloheptanone oxime; cyclooctanone oxime;cyclopentanedione dioxime; cyclohexanedione dioxime; cycloheptanedionedioxime; cyclooctanedione dioxime; isatin dioxime; benzaldehyde oxime;naphthaldehyde oxime; norbornanone oxime; camphor oxime;dimethylglyoxime (H₂DMG); diethylglyoxime; diisopropylglyoxime;ditertbutylglyoxime; dicyanoglyoxime; dicyanamidoglyoxime;diphenylglyoxime (Hdfg); dibenzylglyoxime; dicyclohexylglyoxime;dinorbornylglyoxime; camphorquinone dioxime (Hcqd); nopinoquinonedioxime (Hnqd); butyraldoxime; propionaldoxime; furildioxime; andthienyldioxime.

N—O Valence Stabilizer #13: Examples of carbonyl oximes, bis(carbonyloximes), and 5 poly(carbonyl oximes) (N—O Bidentates, N—O Tridentates,and N—O Tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to: diacetylmonoxime (2,3-butanedione monoxime); benzil monoxime(1,2-diphenylethanedione monoxime); 1,2-dicyclohexylethanedionemonoxime; 1,2-(trifluoromethyl)ethanedione monoxime;1,2-dinorbornylethanedione monoxime; cyclopentanedione monoxime;cyclohexanedione monoxime; cycloheptanedione monoxime; cyclooctanedionemonoxime; camphorquinone oxime; 3-hydroxyiminopentane-2,4-dione; and4-isonitrosopyralozone.

N—O Valence Stabilizer #14: Examples of imine oximes, bis(imine oximes),and poly(imine oximes) (including 2-nitrogen heterocyclic oximes) (N—OBidentates, N—O Tridentates, N—O Tetradentates, and N—O Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 3-(methylimino)butan-2-oneoxime; 4-(methylimino)hexan-3-one oxime;1,2-diphenyl-2-(methylimino)ethan-1-one oxime;1,2-diphenyl-2-(phenylimino)ethan-1-one oxime;1,2-dicyclohexyl-2-(methylimino)ethan-1-one oxime;1,2-dicyclohexyl-2-(cyclohexylimino)ethan-1-one oxime;1,2-dinorbornyl-2-(methylimino)ethan-1-one oxime;N,N′-methylenebis-(3-iminobutan-2-one oxime);N,N′-methylenebis-(4-iminohexan-3-one oxime);N,N′-methylenebis-(1,2-diphenyl-2-iminoethan-1-one oxime);N,N′-methylenebis-(1,2-dicyclohexyl-2-iminoethan-1-one oxime);N,N′-methylenebis-(1,2-dinorbornyl-2-iminoethan-1-one oxime);N,N′-ethylenebis-(3-iminobutan-2-one oxime);N,N′-ethylenebis-(4-iminohexan-3-one oxime);N,N′-ethylenebis-(1,2-diphenyl-2-iminoethan-1-one oxime);N,N′-ethylenebis-(1,2-dicyclohexyl-2-iminoethan-1-one oxime);N,N′-ethylenebis-(1,2-dinorbornyl-2-iminoethan-1-one oxime);N,N′-propylenebis-(3-iminobutan-2-one oxime);N,N′-propylenebis-(4-iminohexan-3-one oxime);N,N′-propylenebis-(1,2-diphenyl-2-iminoethan-1-one oxime);N,N′-propylenebis-(1,2-dicyclohexyl-2-iminoethan-1-one oxime);N,N′-propylenebis-(1,2-dinorbornyl-2-iminoethan-1-one oxime);diacetylazine oxime (Hazio); 2-pyridinaldoxime (Hpao); methyl 2-pyridylketone oxime; ethyl 2-pyridyl ketoxime; phenyl 2-pyridyl ketone oxime(Hppk); benzyl 2-pyridyl ketoxime; di(2-pyridyl) ketone oxime; methyl2-pyrrolyl ketone oxime; ethyl 2-pyrrolyl ketone oxime; phenyl2-pyrrolyl ketone oxime; di(2-pyrrolyl) ketone oxime; andtris(2-aldoximo-6-pyridyl)phosphine.

N—O Valence Stabilizer #15: Examples of hydroxy oximes, bis(hydroxyoximes), and poly(hydroxy oximes) (including 2-oxygen heterocyclicoximes) (N—O Bidentates, N—O Tridentates, N—O Tetradentates, and N—OHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:3-hydroxybutan-2-one oxime; 4-hydroxyhexan-3-one oxime; benzoin oxime(bo)(1,2-diphenyl-2-hydroxyethanone oxime);1,2-di(trifluoromethyl)-2-hydroxyethanone oxime;1,2-dicyclohexyl-2-hydroxyethanone oxime;1,2-dinorbornyl-2-hydroxyethanone oxime; salicylaldoxime (so)(saldox);2-hydroxy-1-naphthaldehyde oxime; 2-furanaldoxime; furildioxime; methyl2-furanyl ketone oxime; ethyl 2-furanyl ketoxime; phenyl 2-furanylketone oxime; benzyl 2-furanyl ketoxime; di(2-furanyl) ketone oxime; and2,5-(oximinomethyl)phenol.

N—O Valence Stabilizer #16: Examples of amino oximes, bis(amino oximes),and poly(amino oximes) (N—O Bidentates, N—O Tridentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 3-(methylamino)butan-2-one oxime (HMeabo);4-(methylamino)hexan-3-one oxime (HEtabo);1,2-diphenyl-2-(methylamino)ethanone oxime (HPhabo);1,2-diphenyl-2-(phenylamino)ethanone oxime;1,2-dicyclohexyl-2-(methylamino)ethanone oxime (HcyHxabo);1,2-dicyclohexyl-2-(cyclohexylamino)ethanone oxime;1,2-di(trifluoromethyl)-2-(methylamino)ethanone oxime;1,2-dinorbornyl-2-(methylamino)ethanone oxime (HNorbabo);N,N′-ethylenebis-(3-aminobutan-2-one oxime)(Haboen);N,N′-ethylenebis-(4-aminohexan-3-one oxime);N,N′-ethylenebis-(1,2-diphenyl-2-aminoethanone oxime);N,N′-ethylenebis-(1,2-dicyclohexyl-2-aminoethanone oxime);N,N′-ethylenebis-(1,2-di(trifluoromethyl)-2-aminoethanone oxime);N,N′-ethylenebis-(1,2-dinorbornyl-2-aminoethanone oxime);N,N′-propylenebis-(3-aminobutan-2-one oxime)(Habopn);N,N′-propylenebis-(4-aminohexan-3-one oxime);N,N′-propylenebis-(1,2-diphenyl-2-aminoethanone oxime);N,N′-propylenebis-(1,2-dicyclohexyl-2-aminoethanone oxime);N,N′-propylenebis-(1,2-di(trifluoromethyl)-2-aminoethanone oxime);N,N′-propylenebis-(1,2-dinorbornyl-2-aminoethanone oxime);2,2′-iminobis(acetamidoxime); 1-diethylamino-3-butanoxime; anddi-2-pyridyl ketone oxime.

N—O Valence Stabilizer #17: Examples of amido oximes, bis(amido oximes),and poly(amido oximes) (N—O Bidentates, N—O Tridentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: formamide oxime; acetamide oxime; propanamide oxime; butanamideoxime; benzamide oxime (Hbamox); naphthamide oxime; diformamide dioxime;salicylamide oxime; and 4-imidazolamide oxime.

N—O Valence Stabilizer #18: Examples of azo oximes, bis(azo oximes), andpoly(azo oximes) (N—O Bidentates, N—O Tridentates, N—O Tetradentates,and N—O Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:acetaldehyde phenylhydrazone oxime; propionaldehyde phenylhydrazoneoxime; and benzaldehyde phenylhydrazone oxime. Also includes hydrazoneoximes.

N—O Valence Stabilizer #19: Examples of 2-nitrosophenols (o-quinonemonoximes) (N—O Bidentates) that meet the requirements for use as “wideband” valence stabilizers for Ce⁺⁴ include, but are not limited to:2-nitrosophenol; 1-nitroso-2-naphthol (Honn); 2-nitroso-1-naphthol(Htnn); 3-nitrosopyrocatechol; 3,6-dinitrosopyrocatechol;2-nitrosoresorcinol; 2,4-dinitrosoresorcinol;2,4,6-trinitrosoresorcinol; 2-nitrosohydroquinone;2,6-dinitrosohydroquinone; 2,3,5,6-tetranitrosohydroquinone;4-nitrosopyrogallol; 4,6-dinitrosopyrogallol; 2-nitrosophloroglucinol;2,4,6-trinitrosophloroglucinol; 7-nitroso-6-hydroxyindazole; PigmentGreen 12 (C.I. 10020); Naphthol Green; and nitroso-R-salt.

N—O Valence Stabilizer #20: Examples of 2-nitrophenols (N—O Bidentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-nitrophenol;2,3-dinitrophenol; 2,4-dinitrophenol; 2,5-dinitrophenol;2,6-dinitrophenol; 2,4,6-trinitrophenol (picric acid);2-amino-4,6-dinitrophenol (picramic acid); 1-nitro-2-naphthol;2-nitro-1-naphthol; 3-nitropyrocatechol; 3,6-dinitropyrocatechol;2-nitroresorcinol; 2,4-dinitroresorcinol; 2,4,6-trinitroresorcinol(styphnic acid); 2-nitrohydroquinone; 2,6-dinitrohydroquinone;2,3,5,6-tetranitrohydroquinone; 4-nitropyrogallol;4,6-dinitropyrogallol; 2-nitrophloroglucinol;2,4,6-trinitrophloroglucinol; dinitrocresol; 7-nitro-6-hydroxyindazole;Dinoseb; Eosin; Naphthol Yellow; and Martius Yellow.

N—O Valence Stabilizer #21: Examples of hydroxamates (hydroxylamines),bis(hydroxamates), and poly(hydroxamates) (N—O Bidentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: acetohydroxamic acid; propianohydroxamic acid; butyrohydroxamicacid; crotonohydroxamic acid; sorbohydroxamic acid; benzohydroxamic acid(BH₂); toluichydroxamic acid; salicylhydroxamic acid (SH₂);phenylacetohydroxamic acid (PhH₂); anthranilhydroxamic acid (AnH₂);nicotinehydroxamic acid (NicH₂); picolinehydroxamic acid;cyclohexanehydroxamic acid (CH₂); quinoline 8-hydroxamic acid (QH₂);cinnamylhydroxamic acid (CnH₂); oxaldihydroxamic acid (OxalH₂);succinylbis-N-phenylhydroxamic acid (SuH₂); adipylbis-N-phenylhydroxamicacid (AdH₂); glyoxalhydroxamic acid (GH₂); 2-thiophenecarbohydroxamicacid; thenoylhydroxamic acid; N-phenylbenzohydroxamic acid;N-tolylbenzohydroxamic acid; N-phenylacetohydroxamic acid;N-phenyl-2-thenoylhydroxamic acid; N-tolyl-2-thenoylhydroxamic acid; andpolyhydroxamic acids.

N—O Valence Stabilizer #22: Examples of N-nitrosohydroxylamines,bis(N-nitrosohydroxylamines), and poly(N-nitrosohydroxylamines) (N—OBidentates, N—O Tetradentates, and N—O Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N-nitrosophenylhydroxylamine(cupferron); N-nitrosonaphthylhydroxylamine (neocupferron);N-nitrosoanthracylhydroxylamine; N-nitroso(2-pyridyl)hydroxylamine; andN-nitroso(2-thiophenyl)hydroxylamine.

N—O Valence Stabilizer #23: Examples of amino acids,ortho-aminocarboxylic acids, peptides,polypeptides, and proteins [N—OBidentates, N—O Tridentates, and N—O Tetradentates; possibly S—Odentates for sulfur-contg. examples such as penicillamine and cystine]that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: alanine (Ala); arginine (Arg);asparagine (Asn); aspartic acid (Asp); cysteine (Cys); cystine (Cys orCys.Cys); dihydroxyphenylalanine (Dopa); glutamic acid (Glu); glutamine(Gln); glycine (Gly); histidine (His); isoleucine (Ile); leucine (Leu);lysine (Lys); methionine (Met); penicillamine (Pen); phenylalanine(Phe); tolylalanine (tala); proline (Pro); sarcosine; serine (Ser);threonine (Thr); tryptophan (Trp); tyrosine (Tyr); and valine (Val) asamino acid examples; 2-pyridinecarboxylic acid (picolinic acid),2-pyrazinecarboxylic acid, 2,3-dicarboxypyrazine, and anthranilic acidas ortho-aminocarboxylic acid examples; Gly-GluO; Hgly-Gly; Gly-MetO;Met-GlyO; Gly-TyrO; Ala-HisO; Gly-His-GlyO; Gly-Gly-His; Gly-Leu-TyrO;penta-GlyO; His-His; triaminoisobutyrate; tetra-GlyO; Pro-Gly; andGly-Met as peptide examples; and azurin, carbonic anhydrase C;carboxypeptidase; concanavalin A; cytochrome b; cytochrome c;erythrocruorin; ferredoxin; haemerythrin; haemoglobin; myoglobin;parvalbumin; albumin; plastocyanin; rubredoxin; superoxide dismutase;thermolysin; and trysin as protein examples; N-acylamino acids;aminocaproic acid; and 3,5-diiodotyrosine.

N—O Valence Stabilizer #24: Examples of amides, bis(amides), andpoly(amides), including lactams (N—O bidentates, N—O tridentates, andN—O tetradentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to: acetamide;propionamide; butanamide; benzamide (benzoylamide)(1-phenylformamide);1-naphthylformamide; toluamide; 1-cyclohexylformamide);1-norbornylformamide; 1-adamantylformamide; N,N-dimethylformamide(DMF)(DMFA); N,N-dimethylacetamide (DMAC); N,N-dimethylbenzamide;N,N-diethylformamide; N,N-diethylacetamide; decanamide; dodecanamide;tetradecanamide; hexadecanamide; octadecanamide; lactobionic acid amide;(hydroxyalkylthio)succinamides; (mercaptoalkoxy)succinamides;polycaproamides; glycinamide; aminoalkylanilides; amidopolyamines (apa);bis(1-phenylethylamide); oxalic semiamide; malonic semiamide; succinicsemiamide; bis(1,1′-benzotriazolyl)dicarboxamide; nicotinamide;acetanilide (N-phenylacetamide); formanilide (N-phenylformamide);benzanilide (N-phenylbenzamide); N-methylformanilide; acetanilide;nicotinanilide; 4′-hydroxyacetanilide (acetaminophen); 2-pyrrolidone;methyl-2-pyrrolidone (NMP); 2-piperidone (valerolactam); caprolactam;polymethylenepolyamine dipropionamide; polyacrylamides; polypyrrolidones[including polyvinylpyrrolidone (povidone)(PVP)]; pyrazolidinones;pyrazolones; diazepinones; N-alkylazaalkene lactams; andN-(2-hydroxyalkyl)azaalkene lactams.

N—O Valence Stabilizer #25: Examples of semicarbazones,bis(semicarbazones), and poly(semicarbazones) (N—O Bidentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: acetaldehyde semicarbazone; acetone semicarbazone; pinacolonesemicarbazone; benzaldehyde semicarbazone; naphthaldehyde semicarbazone;norbornanone semicarbazone; camphor semicarbazone; nopinonesemicarbazone; 2-pyridinaldehyde semicarbazone; salicylaldehydesemicarbazone; quinolinaldehyde semicarbazone; isatin disemicarbazone;camphorquinone disemicarbazone; camphorquinone disemicarbazone;picolinaldehyde semicarbazone; dipyridyl glyoxal disemicarbazone;di-2-pyridyl ketone semicarbazone; methyl-2-pyridyl ketonesemicarbazone; glyoxal disemicarbazone; acetophenone semicarbazone;biacetyl monoxime semicarbazone; acetamidobenzaldehyde semicarbazone;thymolaldosemicarbazone; thiophene-2-aldehyde semicarbazone;phthalaldehyde disemicarbazone; phthalimide disemicarbazone; furaldehydesemicarbazone; naphthoquinone semicarbazone; phenanthrequinonesemicarbazone; cyclohexanedione disemicarbazone; ionone semicarbazone;bissemicarbazone of diethyl-3,4-dioxadioate; and lawsone semicarbazone.

N—O Valence Stabilizer #26: Examples of acyl hydrazones, bis(acylhydrazones), and poly(acyl hydrazones) (N—O Bidentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: acetaldehyde N-formylhydrazone; acetaldehyde N-benzoylhydrazone;acetone N-formylhydrazone; acetone N-benzoylhydrazone; pinacoloneN-formylhydrazone; pinacolone N-benzoylhydrazone; benzaldehydeN-formylhydrazone; benzaldehyde N-benzoylhydrazone; naphthaldehydeN-formylhydrazone; naphthaldehyde N-benzoylhydrazone; norbornanoneN-formylhydrazone; norbornanone N-benzoylhydrazone; camphorN-formylhydrazone; camphor N-benzoylhydrazone; nopinoneN-formylhydrazone; nopinone N-benzoylhydrazone; 2-pyridinaldehydeN-formylhydrazone; 2-pyridinaldehyde N-benzoylhydrazone; salicylaldehydeN-formylhydrazone; salicylaldehyde N-benzoylhydrazone; quinolinaldehydeN-fornylhydrazone; quinolinaldehyde N-benzoylhydrazone; furan-2-aldehydeN-formylhydrazone; furan-2-aldehyde N-benzoylhydrazone; naphthoquinoneN-formylhydrazone; naphthoquinone N-benzoylhydrazone; iononeN-formylhydrazone; ionone N-benzoylhydrazone; lawsone N-formylhydrazone;and lawsone N-benzoylhydrazone.

N—O Valence Stabilizer #27: Examples of carbazones (diazenecarboxylichydrazides), bis(carbazones), and poly(carbazones) (N—O Bidentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diphenylcarbazone; 2-phenylcarbazone; dinaphthylcarbazone; and2-naphthylcarbazone.

N—O Valence Stabilizer #28: Examples of azo compounds with hydroxyl orcarboxy or carbonyl substitution at the ortho- (for aryl) or alpha- orbeta- (for alkyl) positions, Bis[o-(HO-) or alpha- or beta-(HO-)azocompounds], or Poly[o-(HO-) or alpha- or beta-(HO-)azo compounds) (N—OBidentates, N—O Trident ates, N—O Tetradentates, or N—O Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-hydroxyazobenzene[1-(phenylazo)-2-phenol]; 2,2′-dihydroxyazobenzene(o,o′-dihydroxyazobenzene); (2-furan)azobenzene; Direct Blue 2B;1-(4-nitrophenylazo)-2-naphthol; 1-(2-hydroxyphenylazo)-2-naphthol;1-(2-methoxyphenylazo)-2-naphthol; pyridineazo-2-naphthol (PAN);pyridineazoresorcinol (PAR);1-phenyl-4-(2-hydroxyphenylazo)-5-pyrazolone;1-phenyl-4-(2-methoxyphenylazo)-5-pyrazolone;o-hydroxy-o′-(beta-aminoethylamino)azobenzene;2-hydroxy-2′-methoxymethyleneoxyazobenzene; methyl red; turquoise blue(reactive blue); sunset yellow; amaranth; tartrazine; Eriochrome BlackT; tropeolins; Allura Red; amaranth; Acid Alizarin Violet N; Acid Blue29; Acid Orange 8, 63, and 74; Acid Red 1, 4, 8, 37, 88, 97, 114, 151,and 183; Acid Violet 7; Acid Yellow 25, 29, 34, 42, 76, and 99;Brilliant Black BN; Brilliant Crocein; Bordeaux R; Calcion; Chicago SkyBlue; Chromotrope; Cibacron Brilliant Red; Cibacron Brilliant Yellow;Crocein Orange; Crystal Scarlet; Calmagite; Direct Blue 71; Direct Red23, 80, and 81; Direct Violet 51; Direct Yellow 8 and 27; Fast Black;Flavazin; Mordant Blue 9; Mordant Brown 1 and 33; Napthol Blue Black;New Coccine; Nitrazine Yellow; Nitrosulfonazo III; Orange II; Orange G,OT, and B; Ponceau 3R and SX; Polar Yellow; 2-oxazolylazobenzene; and2-benzoxazolylazobenzene.

N—O Valence Stabilizer #29: Examples of diazenefornamides,diazeneacetamides, bis(diazeneformamides), bis(diazeneacetamides),poly(diazeneformamides), and poly(diazeneacetamides) (N—O Bidentates,N—O Tetradentates, and N—O Hexadentates) that meet the requirements foruse as “wide band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazeneformamide, diazeneacetamide, phenyldiazeneformamide,diphenyldiazeneformamide, phenyldiazeneacetamide, anddiphenyldiazeneacetamide.

N—O Valence Stabilizer #30: Examples of diazeneformic acids,diazeneacetic acids, bis(diazeneformic acids), bis(diazeneacetic acids),poly(diazeneformic acids), poly(diazeneacetic acids) and derivativesthereof (N—O Bidentates, N—O Tetradentates, N—O Hexadentates) that meetthe requirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: diazeneformic acid, diazeneacetic acid,phenyldiazeneformic acid, diphenyldiazeneformic acid,phenyldiazeneacetic acid, and diphenyldiazeneacetic acid.

N—O Valence Stabilizer #31: Examples of diazeneformaldehydes,diazeneacetaldehydes, bis(diazeneformaldehydes),bis(diazeneacetaldehydes), poly(diazeneformaldehydes), andpoly(diazeneacetaldehydes) (N—O Bidentates, N—O Tetradentates and N—OHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:diazeneformaldehyde, diazeneacetaldehyde, phenyldiazeneformaldehyde,diphenyldiazeneformaldehyde, phenyldiazeneacetaldehyde, anddiphenyldiazeneacetaldehyde.

N—O Valence Stabilizer #32: Examples of diazenediformamides,diazenediacetamides, bis(diazenediformamides), bis(diazenediacetamides),poly(diazenediformamides), and poly(diazenediacetamides) (N—OTridentates and N—O Hexadentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diazenediformamide, diazenediacetamide, diphenydiazenediformamide,tetraphenyldiazenediformamide, diphenyldiazenediacetamide, andtetraphenyldiazenediacetamide.

N—O Valence Stabilizer #33: Examples of diazenediformic acids,diazenediacetic acids, bis(diazenediformic acids), bis(diazenediaceticacids), poly(diazenediformic acids), poly(diazenediacetic acids) andderivatives thereof (N—O Tridentates and N—O Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: diazenediformic acid, diazenediaceticacid, phenyldiazenediformic acid, diphenyldiazenediformic acid,phenyldiazenediacetic acid, and diphenyldiazenediacetic acid.

N—O Valence Stabilizer #34: Examples of diazenediformaldehydes,diazenediacetaldehydes, bis(diazenediformaldehydes),bis(diazenediacetaldehydes), poly(diazenediformaldehydes), andpoly(diazenediacetaldehydes) (N—O Tridentates and N—O Hexadentates) thatmeet the requirements for use as “wide band” valence stabilizers forCe⁺⁴ include, but are not limited to: diazenediformaldehyde,diazenediacetaldehyde, diphenyldiazenediformaldehyde, anddiphenyldiazenediacetaldehyde.

N—O Valence Stabilizer #35: Examples of ortho-hydroxy (or -carboxy)substituted formazans, bis(o-hydroxy or -carboxy substituted formazans),and poly(o-hydroxy or -carboxy substituted formazans) (N—O Bidentates,N—O Tridentates, N—O Tetradentates, and N—O Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to:1-(2-hydroxyphenyl)-3,5-diphenylformazan;1-(2-methoxyphenyl)-3,5-diphenylformazan;1,5-bis(2-hydroxyphenyl)-3-phenylformazan; and5-bis(2-methoxyphenyl)-3-phenylformazan.

N—O Valence Stabilizer #36: Examples of ortho-hydroxy (or -arboxy)substituted azines (including ketazines), bis(o-hydroxy or carboxysubstituted azines), and poly(o-hydroxy or carboxy substituted azines)(N—O Bidentates, N—O Tridentates, N—O Tetradentates, and N—OHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:2-hydroxy-1-benzalazine; 2-hydroxy-1-naphthalazine; and2-hydroxy-1-cyclohexanonazine.

N—O Valence Stabilizer #37: Examples of Schiff Bases with one Imine(C═N) Group and with ortho- or alpha- or beta-hydroxy or carboxy orcarbonyl substitution (N—O Bidentates, N—O Tridentates, N—OTetradentates, N—O Pentadentates, or N—O Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: N-(Salicylaldehydo)isopropylamine;N-(2-Furfuralo)isopropylamine; N-(2-Acetylfurano)isopropylamine;N-(2-Hydroxyacetophenono)isopropylamine; N-(Pyridoxalo)isopropylamine;N-(Salicylaldehydo)cyclohexylamine; N-(2-Furfuralo)cyclohexylamine;N-(2-Acetylfurano)cyclohexylamine;N-(2-Hydroxyacetophenono)cyclohexylamine; N-(Pyridoxalo)cyclohexylamine;N-(Salicylaldehydo)aniline; N-(2-Furfuralo)aniline (Stenhauz salt);N-(2-Acetylfurano)aniline; N-(2-Hydroxyacetophenono)aniline;N-(Pyridoxalo)aniline; N-(Salicylaldehydo)aminonorbornane;N-(2-Furfuralo)aminonorbornane; N-(2-Acetylfurano)aminonorbornane;N-(2-Hydroxyacetophenono)aminonorbornane; N-(Pyridoxalo)aminonorbornane;(Salicylaldehydo)anisidine; 2-salicylideneiminobenzothiazole;(Salicylaldehydo)sulfamethazine; N′-histidine-3-methoxysalicylidenimine(V-his); N-(o-carboxybenzaldehydo)-2-aminophenol;N-(salicylaldehydo)isatin; N-(2-furfuralo)isatin;N-(2-acetylfurano)isatin; N-(pyridoxalo)isatin;N-(2-hydroxyacetophenono)isatin; hydrofuramide; 2-furancarboxaldehydephenylhydrazone; 2-furancarboxaldehyde 2-pyridyl hydrazone;salicylaldehyde phenylhydrazone; and salicylaldehyde 2-pyridylhydrazone. Also includes hydrazones with ortho-O substitution.

N—O Valence Stabilizer #38: Examples of Schiff Bases with two Imine(C═N) Groups and with ortho- or alpha- or beta-hydroxy or carboxy orcarbonyl substitution (N—O Tridentates, N—O Tetradentates, N—OPentadentates, or N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N,N′-(2,5-Furandicarboxaldehydo)diisopropylamine;N,N′-(2,5-Furandicarboxaldehydo)dicyclohexylamine;N,N′-(2,5-Furandicarboxaldehydo)dianiline; N,N′-(2,5-Furandicarboxaldehydo)di-aminonorbornane;N,N′-(o-Hydroxyphthalicdialdehydo)diisopropylamine;N,N′-(o-Hydroxyphthalicdialdehydo)dicyclohexylamine;N,N′-(o-Hydroxyphthalicdialdehydo)dianiline;N,N′-(o-Hydroxyphthalicdialdehydo)di-aminonorbornane;N,N′-(o-Hydroxyformylcamphoro)diisopropylamine;N,N′-(o-Hydroxyformylcamphoro)dicyclohexylamine;N,N′-(o-Hydroxyformylcamphoro)dianiline;N,N′-(o-Hydroxyformylcamphoro)di-aminonorbornane;N,N′-(o-Hydroxydiacetylbenzeno)diisopropylamine;N,N′-(o-Hydroxydiacetylbenzeno)dicyclohexylamine;N,N′-(o-Hydroxydiacetylbenzeno)dianiline;N,N′-(o-Hydroxydiacetylbenzeno)di-aminonorbornane;N,N′-(3,6-Dihydroxy-1,2-cyclohexanono)diisopropylamine;N,N′-(3,6-Dihydroxy-1,2-cyclohexanono)dicyclohexylamine;N,N′-(3,6-Dihydroxy-1,2-cyclohexanono)dianiline;N,N′-(3,6-Dihydroxy-1,2-cyclohexanono)di-aminonorbornane;N,N′-(2,5-Diacetylfurano)diisopropylamine;N,N′-(2,5-Diacetylfurano)dicyclohexylamine;N,N′-(2,5-Diacetylfurano)dianiline;N,N′-(2,5-Diacetylfurano)di-aminonorbornane;N,N′-(Salicylaldehydo)ethylenediaamine;N,N′-(o-Hydroxynaphthaldehydo)ethylenediamine;N,N′-(o-Hydroxyacetophenono)ethylenediamine;N,N′-(Salicylaldehydo)trimethylenediamine;N,N′-(o-Hydroxynaphthaldehydo)trimethylenediamine;N,N′-(o-Hydroxyacetophenono)trimethylenediaamine;N,N′-(Salicylaldehydo)cyclohexane-1,2-diamine;N,N′-(o-Hydroxynaphthaldehydo)cyclohexane-1,2-diamine;N,N′-(o-Hydroxyacetophenono)cyclohexane-1,2-diamine;N,N′-(Salicylaldehydoy)-1,2-diaminobenzene;N,N′-(o-Hydroxynaphthaldehydo)-1,2-diaminobenzene;N,N′-(o-Hydroxyacetophenono)-1,2-diaminobenzene;N,N′-bis(salicylaldehydo)-1,12-diaminododecane (Saldn);N,N′-bis(3-methoxysalicylaldehydopo-phenyldiamine;N,N′-bis(3,4-difluorobenzaldehydo)-4,4′-benzidine; andN,N′-phenylenebis(3-methoxysalicylidenimine) (V-ph-V). Also includeshydrazones with ortho-O substitution.

N—O Valence Stabilizer #39: Examples of Schiff Bases with three Imine(C═N) Groups and with ortho- or alpha- or beta-hydroxy or carboxy orcarbonyl substitution (N—O Tetradentates, N—O Pentadentates, or N—OHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:N,N′,N″-(Salicylaldehydo)tris(2-aminoethyl)amine;N,N′,N″-(o-Hydroxynaphthaldehydo)tris(2-aminoethyl)amine; andN,N′,N″-(o-Hydroxyacetophenono)tris(2-aminoethyl)amine. Also includeshydrazones with ortho-O substitution.

N—O Valence Stabilizer #40: Examples of silylaminoalcohols (N—OBidentates, N—O Tridentates, N—O Tetradentates, and N—O Hexadentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: silatranes.

N—O Valence Stabilizer #41: Examples of hydroxyalkyl imines (iminoalcohols) (N—O Bidentates, N—O Tridentates, N—O Tetradentates, and N—OHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:2-hydroxycyclohexylimine; 3-hydroxy-2-iminonorbornane;2,2′-diiminodicyclohexyl ether; oxamide; 3-imino-1,5-pentanedialdehyde;iminodiacetic acid; and iminodipropionic acid.

N—O Valence Stabilizer #42: Examples of hydroxyaryl amines andhydroxyaryl imines (N—O Bidentates, N—O Tridentates, N—O Tetradentates,and N—O Hexadentates) that meet the requirements for use as “wide band”valence stabilizers for Ce⁺⁴ include, but are not limited to:2-aminophenol; 2-aminobenzoic acid (anthranilic acid); 2-aminoanisole;o-phenetidine; o-anisidine; 2-hydroxymethyl)-alpha-aminotoluene;1-amino-2-naphthol; 2-amino-1-naphthol;2,2′-di(aminomethyl)diphenylketone; isophoronediamine;tris-2,4,6-dimethylaminomethyl phenol; di(2-amino)phenyl ether;1,3-di(2-amino)phenyl-2-hydroxypropane;1,3-di(3-amino)phenyl-2-hydroxypropane;1,3-di(2-hydroxy)phenyl-2-aminopropane;1,3-di(3-hydroxy)phenyl-2-aminopropane; 2,2′-dihydroxyiminodibenzyl;2,2′-iminodibenzoic acid; 2,2′-dihydroxyiminostilbene;poly(o-phenetidine); poly(o-aminophenol); poly(o-anisidine); and3-(anilino)propionamide.

N—O Valence Stabilizer #43: Examples of five-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional oxygen atom binding site not in a ring (N—O Bidentates, N—OTridentates, N—O Tetradentates, or N—O Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-hydroxypyrrole;2-(methylhydroxy)methylpyrrole; 2,5-(hydroxymethyl)pyrrole;2,5-(methylhydroxymethyl)pyrrole; imidazoline2-one (2-hydroxyimidazole);2-hydroxythiazoline; 2-hydroxybenzimidazole; 2-hydroxybenzothiazole;2-hydroxybenzoxazole; 2-hydantoin; di-2-pyridylglyoxal (2,2′-pyridi);bis((1-pyrazolyl)methane)ether; bis(2-(1-pyrazol yl)ethane)ether;bis(benzimidazolylmethane)ether; bis(benzimidazolylethane)ether;tris(imidazolyl)methanol; tris(imidazolylmethane)methanol;N-hydroxymethyl-N,N-(benzimidazolylmethane)amine;N-(2-hydroxyethyl)-N,N-(benzimidazolylmethane)amine;N,N′-di(benzimidazolylmethane)-1,3-diamino-2-hydroxypropane;N,N,N′,N′-tetrakis(benzimidazolylmethane)-1,3-diamino-2-hydroxypropane;bis(N,N-((4-imidazolyl)methane)-2-aminoethane)ether;4-carboxybenzotriazole; antipyrine; 4-aminoantipyrine (aap); hydantoin;aminoalkylhydantoins; 2,5-oxazolidinedione; benzyldibenzoyltriazole(bdbt); 5-hydroxymethylimidazole; dicarboxyalkylbenzotriazoles;bis(hydroxyphenyl)aminotriazoles; pyrrole-2-carboxaldehyde;(oxopyrrolidinylalkyl)triazoles; alkoxybenzotriazoles;aryloxybenzotriazoles; 3-salicylamido-4,5-dihydro-1,2,4-triazole;5-(alkoxy)benzotriazole; (polyoxyalkylene)oxazolidines;1-(dialkylaminomethyl)-5-carboxyalkylbenzotriazole;1-(2-hydroxyethyl)imidazoline; 1-acetoxyimidazole; 1-acetylimidazole;benzotriazolecarboxylic acid; poly(oxyalkylated)pyrazoles;poly(oxyalkylated)thiadiazoles; 1,2,4triazole-3-carboxylic acid;5-hydroxypyrazole; 3-phenyl-1,2,4-triazol-5-one (ptr);1-acetylbenzimidazole; 1-[(acetoxy)ethyl]benzimidazole; creatinine;indole-2-carboxylic acid; pyrrole-2-carboxylic acid;imidazole-2-carboxylic acid; pyrazole-2-carboxylic acid; and1,1′-oxalyldiimidazole.

N—O Valence Stabilizer #44: Examples of six-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional oxygen atom binding site not in a ring (N—O Bidentates, N—OTridentates, N—O Tetradentates, or N—O Hexadentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: 4-aminomethyl-3-pyridinemethanol(including pyridoxamine); 2-hydroxypyridine;2-(methylhydroxy)methylpyridine; 2-(2-(methylhydroxy)ethyl)pyridine;2,6-(hydroxymethyl)pyridine; 2,6-(methylhydroxymethyl)pyridine;2-hydroxypyrimidine; 2-dihydroxymethylpyrimidine; 2-hydroxyquinoline;8-hydroxyquinoline (oxine); 8-methylhydroxyquinoline;2-hydroxyquinazoline; orotic acid(1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic acid)(6-uracilcarboxylic acid); 1-methylpyrimidine-2-one; uracil;6-hydroxypurine;bis(N,N,N′,N′-tetra(2-(2-pyridyl)ethane)aminomethane)ether;bis(N,N,N′,N′-tetra(2-(2-pyridyl)ethane)aminoethane)ether;quinazol-4-one; quinazol-2-one; 5-azathymine; 2-hydroxybenzimidazole(2-hbz); guanine; 1,3,5-triazin-6-one; 6-hydroxy-1,3,5-triazine;4,6-dihydroxy-1,3,5-triazine; triazine carboxylic acids;2,3-dihydroxypyridine; thiomorpholin-3-one;hydroxytetrahydropyrimidines; 2-piperazinones; 2-piperidinones;dilituric acid; actinoquinol; caffeine; citrazinic acid; picolinic acid;2-quinolol; 2,6-dimethoxypyridine; quinoxaline-2-carboxylic acid;flucytosine; hypoxanthine; hexamethylolmelamine; hydroorotic acid;isoorotic acid; xanthine; leucopterin; nitroorotic acid; 8-azaguanine;and cyanuric acid.

N—O Valence Stabilizer #45: Examples of five-membered heterocyclic ringscontaining one or two oxygen atoms at least one additional nitrogen atombinding site not in a ring (N—O Bidentates, N—O Tridentates, N—OTetradentates, or N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-aminofuran; 2,5-diaminofuran; 2-aminomethylfuran;2,5-di(aminomethyl)furan; 2-aminobenzofuran; and 2-amino-1,3-dioxolane.N—O Valence Stabilizer #46: Examples of six-membered heterocyclic ringscontaining one or two oxygen atoms at least one additional nitrogen atombinding site not in a ring (N—O Bidentates, N—O Tridentates, N—OTetradentates, or N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-aminopyran; 2,6-diaminopyran; 2-aminomethylpyran;2,6-di(aminomethyl)pyran; and 2-aminobenzopyran.

N—O Valence Stabilizer #47: Examples of five-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional oxygen atom binding site in a separate ring (N—O Bidentates,N—O Tridentates, N—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-(2-furan)pyrrole; 2,5-di(2-furan)pyrrole; 2-(2-pyran)pyrrole;2,5-di(2-pyran)pyrrole; 2,5-di(2-pyrrole)furan; and2,6-di(2-pyrrole)pyran.

N—O Valence Stabilizer #48: Examples of six-membered heterocyclic ringscontaining one, two, three, or four nitrogen atoms at least oneadditional oxygen atom binding site in a separate ring (N—O Bidentates,N—O Tridentates, N—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2-(2-furan)pyridine; 2,6-di(2-furan)pyridine; 2-(2-pyran)pyridine;2,6-di(2-pyran)pyridine; 2,5-di(2-pyridyl)furan; 2,6-di(2-pyridyl)pyran;and drometrizole.

N—O Valence Stabilizer #49: Examples of two-, three-, four-, six-,eight-, and ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of nitrogen(usually amine or imine groups) or oxygen (usually hydroxy, carboxy, orcarbonyl groups) and are not contained in component heterocyclic rings(N—O Bidentates, N—OTridentates, N—O Tetradentates, and N—OHexadentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to: azaoxacyclobutane([4]aneNO); azaoxacyclopentane ([5]aneNO); azaoxacyclohexane ([6]aneNO);azaoxacycloheptane ([7]aneNO); azaoxacyclooctane ([8]aneNO);azaoxacyclobutene ([4]eneNO); azaoxacyclopentene ([5]eneNO);azaoxacyclohexene ([6]eneO); azaoxacycloheptene ([7]eneO);azaoxacyclooctene ([8]eneNO); azaoxacyclobutadiene ([4]dieneNO);azaoxacyclopentadiene ([5]dieneNO); azaoxacyclohexadiene ([6]dieneNO);azaoxacycloheptadiene ([7]dieneNO); azaoxacyclooctadiene ([8]dieneNO);diazaoxacyclohexane ([6]aneON₂); diazaoxacycloheptane ([7]aneON₂);diazaoxacyclooctane ([8]aneON₂); diazaoxacyclononane ([9]aneON₂);diazaoxacyclodecane ([10]aneON₂); diazaoxacycloundecane ([11]aneON₂);diazaoxacyclododecane ([12]aneON₂); diazaoxacyclohexene ([6]eneON₂);diazaoxacycloheptene ([7]eneON₂); diazaoxacyclooctene ([8]eneON₂);diazaoxacyclononene ([9]eneON₂); diazaoxacyclodecene ([10]eneON₂);diazaoxacycloundecene ([11]eneON₂); diazaoxacyclododecene ([12]eneON₂);diazadioxacyclooctane ([8]aneO₂N₂); diazadioxacyclononane ([9]aneO₂N₂);diazadioxacyclodecane ([10]aneO₂N₂); diazadioxacycloundecane([11]aneO₂N₂); diazadioxacyclododecane ([12]aneO₂N₂);diazadioxacyclotridecane ([13]aneO₂N₂); diazadioxacyclotetradecane([14]aneO₂N₂); diazadioxacyclopentadecane ([15]aneO₂N₂);diazadioxacyclohexadecane ([16]aneO₂N₂); diazadioxacycloheptadecane([17]aneO₂N₂); diazadioxacyclooctadecane ([18]aneO₂N₂);diazadioxacyclononadecane ([19]aneO₂N₂); diazadioxacycloeicosane([20]aneO₂N₂); diazadioxacyclooctadiene ([8]dieneO₂N₂);diazadioxacyclononadiene ([9]dieneO₂N₂); diazadioxacyclodecadiene([10]dieneO₂N₂); diazadioxacycloundecadiene ([11]dieneO₂N₂);diazadioxacyclododecadiene ([12]dieneO₂N₂); diazadioxacyclotridecadiene([13]dieneO₂N₂); diazadioxacyclotetradecadiene ([14]dieneO₂N₂);diazadioxacyclopentadecadiene ([15]dieneO₂N₂);diazadioxacyclohexadecadiene ([16]dieneO₂N₂);diazadioxacycloheptadecadiene ([17]dieneO₂N₂);diazadioxacyclooctadecadiene ([18]dieneO₂N₂);diazadioxacyclononadecadiene ([19]dieneO₂N₂); anddiazadioxacycloeicosadiene ([20]dieneO₂N₂).

N—O Valence Stabilizer #50: Examples of four-, six-, eight-, orten-membered macrocyclics, macrobicyclics, and macropolycyclics(including catapinands, cryptands, cyclidenes, and sepulchrates) whereinall binding sites are composed of nitrogen or oxygen and are containedin component hetero cyclic rings (N—O Bidentates, N—O Tridentates, N—OTetradentates, or N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dipyrandipyridines; difurandipyrroles; tripyrantripyridines;trifurantripyrroles; tetrapyrantetrapyridines; andtetrafurantetrapyrroles.

N—O Valence Stabilizer #51: Examples of four-, six-, eight-, orten-membered macrocyclics, macrobicyclics, and macropolycyclics(including catapinands, cryptands, cyclidenes, and sepulchrates) whereinall binding sites are composed of nitrogen or oxygen and are containedin a combination of heterocyclic rings and amine, imine, hydroxy,carboxy, or carbonyl groups (N—O Bidentates, N—O Tridentates, N—OTetradentates, or N—O Hexadentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: azaoxatetraphyrins; diazadioxatetraphyrins; azaoxahexaphyrins;diazadioxahexaphyrins; and triazatrioxahexaphyrins.

S—O Valence Stabilizer #1: Examples of 1,3-monothioketones(monothio-beta-ketonates), 1,3,5-monothioketones, 1,3,5-dithioketones,bis(1,3-monothioketones), and poly(1,3-monothioketones) (S—O Bidentates,S—O Tridentates, S—O Tetradentates) that meet the requirements for useas “wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: hexafluoropenta-2-thione-4-ketone;1,3-diphenyl-1,3-propana-1-thione-3-ketone; benzoylthiopinacolone;cyclohexoylthiocyclohexoylmethane; diphenylpentanedithionate;tetramethylnonanedithionate; hexafluoroheptanedithionate;trifluoroheptanedithionate; 1-(2-thienyl)-butan-1-thione-3-ketone,1-(2-naphthyl)-butan-1-thione-3-ketone, and trifluoroacetylthiocamphor.

S—O Valence Stabilizer #2: Examples of thiomalonamides(thiomalonodiamides), bis(thiomalonamides), and polythiomalonamides (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: thiomalonamide, N-phenylthiomalonamide,N-benzylthiomalonamide, N-pentafluorophenylthiomalonamide,N-cyclohexylthiomalonamide, N-norbornylthiomalonamide,N,N′-diphenylthiomalonamide, N,N′-dibenzylthiomalonamide,N,N′-dipentafluorophenylthiomalonamide, N,N′-dicyclohexylthiomalonamide,and N,N′-norbornylthiomalonamide.

13 O Valence Stabilizer #3: Examples of 2-thioacylacetamides,2-acylthioacetamides, bis(2-thioacylacetamides),bis(2acylthioacetamides), poly(2-thioacylacetamides), andpoly(2-Acylthioacetamides) (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce^(′4) include, but are not limited to:2-acetothioacetamide, 2-thioacetoacetamide,N-phenyl-2-acetothioacetamide, N-pentafluorophenyl-2-acetothioacetamide,N-benzyl-2-acetothioacetamide, N-cyclohexyl-2-acetothioacetamide,N-norbornyl-2-acetothioacetamide, N-phenyl-2-benzothioacetamide,N-pentafluorophenyl-2-pentafluorobenzothioacetamide, andN-cyclohexyl-2-cyclohexothioacetamide.

S—O Valence Stabilizer #4: Examples of dithiodicarbonic diamides,bis(dithiodicarbonic diamides), and poly(dithiodicarbonic diamides) (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiodicarbonic diamide;N-phenyldithiodicarbonic diamide; N-pentafluorophenyldithiodicarbonicdiamide; N-benzyldithiodicarbonic diamide; N-cyclohexyldithiodicarbonicdiamide; N-norbornyldithiodicarbonic diamide;N,N′-diphenyldithiodicarbonic diamide;N,N′-dipentafluorophenyldithiodicarbonic diamide;N,N′-dibenzyldithiodicarbonic diamide; N,N′-dicyclohexyldithiodicarbonicdiamide; and N,N′-dinorbornyldithiodicarbonic diamide.

S—O Valence Stabilizer #5: Examples of monothiohypophosphoric acids,bis(monothiohypophosphoric acids), poly(monothiohypophosphoric acids),and derivatives thereof (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “wide band” valencestabilizers for Ce⁺⁴ include, but are not limited to:monothiohypophosphoric acid, methylmonothiohypophosphoric acid,isopropylmonothiohypophosphoric acid, tert-butylmonothiohypophosphoricacid, phenylmonothiohypophosphoric acid,pentafluorophenylmonothiohypophosphoric acid,benzylmonothiohypophosphoric acid, cyclohexylmonothiohypophosphoricacid, norbornylmonothiohypophosphoric acid,dimethylmonothiohypophosphoric acid, diisopropylmonothiohypophosphoricacid, di-tert-butylmonothiohypophosphoric acid,diphenylmonothiohypophosphoric acid,di-pentafluorophenylmonothiohypophosphoric acid,dibenzylmonothiohypophosphoric acid, dicyclohexylmonothiohypophosphoricacid, and dinorbornylmonothiohypophosphoric acid.

S—O Valence Stabilizer #6: Examples of monothiohypophosphoramides,bis(monothiohypophosphoramides), and poly(monothiohypophosphoramides)(S—O Bidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothiohypophosphoramide,N-methylmonothiohypophosphoramide, N-isopropylmonothiohypophosphoramide,N-tert-butylmonothiohypophosphoramide,N-phenylmonothiohypophosphoramide,N-pentafluorophenylmonothiohypophosphoramide,N-benzylmonothiohypophosphoramide,N-cyclohexylmonothiohypophosphoramide,N-norbornylmonothiohypophosphoramide,N,N′″-dimethylmonothiohypophosphoramide,N,N′″-diisopropylmonothiohypophosphoramide,N,N′″-di-tert-butylmonothiohypophosphoramide,N,N′″-diphenylmonothiohypophosphoramide,N,N′″-di-pentafluorophenylmonothiohypophosphoramide,N,N′″-dibenzylmonothiohypophosphoramide,N,N′″-dicyclohexylmonothiohypophosphoramide, andN,N′″-dinorbornylmonothiohypophosphoramide.

S—O Valence Stabilizer #7: Examples of monothioimidodiphosphoric acids,monothiohydrazidodiphosphoric acids, bis(monothioimidodiphosphoricacids), bis(monothiohydrazidodiphosphoric acids),poly(monothioimidodiphosphoric acids),poly(monothiohydrazidodiphosphoric acids), and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothioimidodiphosphoric acid,methylmonothioimidodiphosphoric acid, isopropylmonothioimidodiphosphoricacid, tert-butylmonothioimidodiphosphoric acid,phenylmonothioimidodiphosphoric acid,pentafluorophenylmonothioimidodiphosphoric acid,benzylmonothioimidodiphosphoric acid,cyclohexylmonothioimidodiphosphoric acid,norbornylmonothioimidodiphosphoric acid,dimethylmonothioimidodiphosphoric acid,diisopropylmonothioimidodiphosphoric acid,di-tert-butylmonothioimidodiphosphoric acid,diphenylmonothioimidodiphosphoric acid,di-pentafluorophenylmonothioimidodiphosphoric acid,dibenzylmonothioimidodiphosphoric acid,dicyclohexylmonotbioimidodiphosphoric acid, anddinorbornylmonothioimidodiphosphoric acid.

S—O Valence Stabilizer #8: Examples of monothioimidodiphosphoramides,monothiohydrazidodiphosphoramides, bis(monothioimidodiphosphoramides),bis(monothiohydrazidodiphosphoramides),poly(monothioimidodiphosphoramides), andpoly(monothiohydrazidodiphosphoramides) (S—O Bidentates, S—OTridentates, S—O Tetradentates) that meet the requirements for use as“wide band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: monothioimidodiphosphoramide, N-methylmonothioimidodiphosphoramide,N-isopropylmonothioimidodiphosphoramide,N-tert-butylmonothioimidodiphosphoramide,N-phenylmonothioimidodiphosphoramide,N-pentafluorophenylmonothioimidodiphosphoramide,N-benzylmonothioimidodiphosphoramide,N-cyclohexylmonothioimidodiphosphoramide,N-norbornylmonothioimidodiphosphoramide,N,N′″-dimethylmonothioimidodiphosphoramide,N,N′″-diisopropylmonothioimidodiphosphoramide,N,N′″-di-tert-butylmonothioimidodiphosphoramide,N,N′″-diphenylmonothioimidodiphosphoramide,N,N′″-di-pentafluorophenylmonothioimidodiphosphoramide,N,N′″-dibenzylmonothioimidodiphosphoramide,N,N′″-dicyclohexylmonothioimidodiphosphoramide, andN,N′″-dinorbornylmonothioimidodiphosphoramide.

S—O Valence Stabilizer #9: Examples of monothiodiphosphoramides,bis(monothiodiphosphoramides), and poly(monothiodiphosphoramides) (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothiodiphosphoramide,N-methylmonothiodiphosphoramide, N-isopropylmonothiodiphosphoramide,N-tert-butylmonothiodiphosphoramide, N-phenylmonothiodiphosphoramide,N-pentafluorophenylmonothiodiphosphoramide,N-benzylmonothiodiphosphoramide, N-cyclohexylmonothiodiphosphoramide,N-norbornylmonothiodiphosphoramide,N,N′″-dimethylmonothiodiphosphoramide,N,N′″-diisopropylmonothiodiphosphoramide,N,N′″-di-tert-butylmonothiodiphosphoramide,N,N′″-diphenylmonothiodiphosphoramide,N,N′″-di-pentafluorophenylmonothiodiphosphoramide,N,N′″-dibenzylmonothiodiphosphoramide,N,N′″-dicyclohexylmonothiodiphosphoramide, andN,N′″-dinorbornylmonothiodiphosphoramide.

S—O Valence Stabilizer #10: Examples of monothiodiphosphoric acids,bis(monothiodiphosphoric acids), poly(monothiodiphosphoric acids), andderivatives thereof (S—O Bidentates, S—O Tridentates, S—O Tetradentates)that meet the requirements for use as “wide band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: monothiodiphosphoric acid,methylmonothiodiphosphoric acid, isopropylmonothiodiphosphoric acid,tert-butylmonothiodiphosphoric acid, phenylmonothiodiphosphoric acid,pentafluorophenylmonothiodiphosphoric acid, benzylmonothiodiphosphoricacid, cyclohexylmonothiodiphosphoric acid, norbornylmonothiodiphosphoricacid, dimethylmonothiodiphosphoric acid, diisopropylmonothiodiphosphoricacid, di-tert-butylmonothiodiphosphoric acid,diphenylmonothiodiphosphoric acid,di-pentafluorophenylmonothiodiphosphoric acid,dibenzylmonothiodiphosphoric acid, dicyclohexylmonothiodiphosphoricacid, and dinorbornylmonothiodiphosphoric acid.

S—O Valence Stabilizer #11: Examples of monothiocarbamates,bis(monothiocarbamates), and poly(monothiocarbamates) (includingN-bydroxymonothiocarbamates and N-mercaptomonothiocarbamates) (S—OBidentates, S—O Tridentates, and S—O Tetradentates) that meet therequirements for use as “wide band” valence stabilizers for Ce⁺⁴include, but are not limited to: dimethylmonothiocarbamate (dmmtc);di(trifluorodimethyl)monothiocarbamate; diethylmonothiocarbamate(demtc); dipropylmonothiocarbamate; diisopropylmonothiocarbamate;dibutylmonothiocarbamate; ditertbutylmonothiocarbamate;dicyanamidomonothiocarbamate; diphenylmonothiocarbamate;di(pentafluorophenyl)monothiocarbamate; dibenzylmonothiocarbamate;dinaphthylmonothiocarbamate; dicyclohexylmonothiocarbamate;dinorbornylmonothiocarbamate; diadamantylmonothiocarbamate;pyrrolidinomonothiocarbamate (pyrmtc); piperidinomonothiocarbamate(pipmtc); morpholinomonothiocarbamate (mormtc);thiamorpholinomonothiocarbamate; 3-pyrrolinomonothiocarbamate;pyrrolomonothiocarbamate; oxazolomonothiocarbamate;isoxazolomonothiocarbamate; thiazolomonothiocarbamate;isothiazolomonothiocarbamate; indolomonothiocarbamate;carbazolomonothiocarbamate; pyrazolinomonothiocarbamate;imidazolinomonothiocarbamate; pyrazolomonothiocarbamate;imidazolomonothiocarbamate; indazolomonothiocarbamate; andtriazolomonothiocarbamate.

Water-soluble precursors for the organic valence stabilizers aretypically used to ensure that sufficient material is available forcoating deposition from aqueous solutions. Identification of suitablewater-soluble precursors can be difficult because many of these organicsdo not form a wide range of water-soluble compounds.

As with the inorganic valence stabilizers, crosses between two or moreorganic valence stabilizers can be used to stabilize Ce⁺⁴ for corrosionprotection. For example, in some instances it may be desirable to form avalence stabilizer out of a beta-diketone and an amine ligand. Both ofthese materials can complex to form a mixed beta-diketone/amine valencestabilizer out of the conversion coating solution during the coatingprocess.

4c) Narrow Band Inorganic Valence Stabilizers for Ce⁺⁴

Narrow band valence stabilizers can be used to stabilize Ce⁺⁴ forcorrosion protection, but they are less typical. Narrow band valencestabilizers exhibit some limitation in their use when compared to wideband stabilizers. They may be toxic or may complex Ce⁺⁴ only withdifficulty. These narrow band stabilizers include, but are not limitedto, bismuthates, germanates, arsenates, and selenates. For example,valence stabilizers using arsenate are less desirable because theirinherent toxicity is very large (greater than hexavalent chromium),although they may be very effective at inhibiting corrosion when usedwith Ce⁺⁴. Arsenates can be used as valence stabilizers for Ce⁺⁴ whenthe toxicity of the coating solution is not a factor in its use.

Other narrow band stabilizers may result in Ce⁺⁴-stabilizer complexeswith limited stability, an undesirable solubility range, or limitedelectrostatic characteristics, and they would be useful only in limitedapplications. Formation of a protective shell of octahedra or icosahedrawith borates (B⁺³), aluminates (Al⁺³), silicates (Si⁺⁴) titanates(Ti⁺⁴), or zirconates (Zr⁺⁴the Ce⁺⁴ ion is difficult but possible. Thesecompounds are known to form octahedra or icosahedra, but tend topolymerize in chain-like structures when precipitated from aqueoussolution under ambient conditions. These and other narrow bandstabilizers can provide some degree of corrosion protection whencomplexed with Ce⁺⁴, but will not necessarily perform with the sameefficiency as the wide band stabilizers by themselves. Combinations ofthese materials, such as phosphosilicates, aluminosilicates, orborosilicates may also function as narrow band inorganic valencestabilizers.

Narrow band inorganic stabilizers used in combination with wide bandinorganic stabilizers described above can be used to provide significantcorrosion protection. Conversely, modifications of wide band inorganicvalence stabilizers can result in a complex with reduced corrosioninhibition. For example, heteropolymetallates can contain ions inaddition to the desired Ce⁺⁴ ion.

The central cavity of the heteropolymetallates can contain ions inaddition to the desired Ce⁺⁴ ion. For example, the use ofsilicomolybdates, phosphomolybdates, silicotungstates, andphosphotungstates is possible. In these Ce⁺⁴-valence stabilizercomplexes, Si⁺⁴ or P⁺⁵ ions also occupy the central cavity of thecomplex with the Ce⁺⁴ ion. The inclusion of additional ions in thecentral cavity reduces the stability of the complex, and thereby leadsto lower corrosion protection. Nonetheless, these complexes alsodemonstrated some corrosion-inhibiting activity.

The additional ions that can be included within the central cavity ofthe heteropolymetallates described above depend upon the size of thecentral cavity, which in turn depend upon the specific chemistryexhibited by an inorganic valence stabilizer (e.g., molybdate,tungstate, periodate, carbonate, etc.). In general, these additionalions must also be small so as to ensure the stability of the formedCe⁺⁴-valence stabilized complex. Examples of small additional ionsinclude, but are not limited to: B⁺³, Al⁺³, Si⁺⁴, P⁺⁵, Ti+⁴, V⁺⁵, V⁺⁴,V⁺⁴, Cr⁺⁶, Cr³⁰ ⁴, Cr⁺³, Mn⁺⁴, Mn⁺³, Mn⁺², Fe⁺³, Fe⁺², Co⁺², Co⁺³, Ni⁺²,Ni⁺³, Ni⁺⁴, Cu⁺², Cu⁺³, Zn⁺², Ga⁺³, Ge⁺⁴, As⁺⁵, As⁺³, and Zr⁺⁴.

Water-soluble precursors for these materials are desirable. Typically,the free acids (e.g., silicomolybdic acid, phosphotungstic acid,borotungstic acid, etc.) offer the most water-soluble precursors forthese materials.

4d) Narrow Band Organic Valence Stabilizers for Ce⁺⁴

Narrow band organic valence stabilizers include those general classes ofchemical compounds that result in Ce⁺⁴-valence stabilizer complexes thatare either less stable, more soluble in water, or more toxic than thewide band organic stabilizers. Some of the typical “narrow band” organicvalence stabilizer species are listed in Table 2 below.

TABLE 2 Narrow Band Organic Valence Stabilizers for the Ce⁺⁴ Ion GeneralStructural Name (Type of Organic) Structural Representation N ValenceStabilizer #1: Macrocyclic ligands containing five, seven, or Five-,Seven-, or Nine-Membered nine nitrogen binding sites to valencestabilize Macrocyclics, Macrobicyclics, and the central metal ion. Caninclude other Macropolycyclics (including Catapinands, hydrocarbon orring systems bound to this Cryptands, Cyclidenes, and Sepulchrates)macrocyclic ligand, but they do not coordinate wherein all Binding Sitesare composed of with the stabilized, high valence metal ion. ThisNitrogen (usually amine or imine groups) ligand and/or attached,uncoordinating and are not contained in Component hydrocarbons/rings mayor may not have Heterocyclic Rings (N—N Tridentates, N—N halogen orpolarizing or water- Tetradentates, and N—N Hexadentates)insolubilizing/solubilizing groups attached. N Valence Stabilizer #2:Macrocyclic ligands containing a total of five or Five-, orSeven-Membered Macrocyclics, seven five-membered heterocyclic ringsMacrobicyclics, and Macropolycyclics containing nitrogen binding sites.Can include (including Catapinands, Cryptands, other hydrocarbon/ringsystems bound to this Cyclidenes, and Sepulchrates) wherein allmacrocyclic ligand, but they do not coordinate Binding Sites arecomposed of Nitrogen with the stabilized, high valence metal ion. Thisand are contained in Component 5- ligand and/or attached, uncoordinatingMembered Heterocyclic Rings (N—N hydrocarbon/rings may or may not havehalogen Tridentates, N—N Tetradentates, or N—N or polarizing orwater-insolubilizing groups Hexadentates) attached. N Valence Stabilizer#3: Macrocyclic ligands containing at least one 5- Five-, Seven-, orNine-Membered membered heterocyclic ring. These Macrocyclics,Macrobicyclics, and heterocyclic rings provide nitrogen binding sitesMacropolycyclics (including Catapinands, to valence stabilize thecentral metal ion. Other Cryptands, Cyclidenes, and Sepulchrates) amineor imine binding sites can also be wherein all Binding Sites arecomposed of included in the macrocyclic ligand, so long as Nitrogen andare contained in a the total number of binding sites is five, seven,Combination of 5-Membered Heterocyclic or nine. Can include otherhydrocarbon/ring Rings and Amine or Imine Groups (N—N systems bound tothis macrocyclic ligand, but Tridentates, N—N Tetradentates, or N—N theydo not coordinate with the stabilized, high Hexadentates) valence metalion. This ligand and/or attached, uncoordinating hydrocarbon/rings mayor may not have halogen or polarizing or water- insolubilizing groupsattached. N Valence Stabilizer #4: Macrocyclic ligands containing atotal of five or Five- or Seven-Membered Macrocyclics, sevensix-membered heterocyclic rings Macrobicyclics, and Macropolycyclicscontaining nitrogen binding sites. Can include (including Catapinands,Cryptands, other hydrocarbon/ring systems bound to this Cyclidenes, andSepulchrates) wherein all macrocyclic ligand, but they do not coordinateBinding Sites are composed of Nitrogen with the stabilized, high valencemetal ion. This and are contained in Component 6- ligand and/orattached, uncoordinating Membered Heterocyclic Rings (N—Nhydrocarbon/rings may or may not have halogen Tridentates, N—NTetradentates, or N—N or polarizing or water-insolubilizing groupsHexadentates) attached. N Valence Stabilizer #5: Macrocyclic ligandscontaining at least one 6- Five-, Seven-, or Nine-Membered memberedheterocyclic ring. These Macrocyclics, Macrobicyclics, and heterocyclicrings provide nitrogen binding sites Macropolycyclics (includingCatapinands, to valence stabilize the central metal ion. OtherCryptands, Cyclidenes, and Sepulchrates) amine or imine binding sitescan also be wherein all Binding Sites are composed of included in themacrocyclic ligand, so long as Nitrogen and are contained in a the totalnumber of binding sites is five, seven, Combination of 6-MemberedHeterocyclic or nine. Can include other hydrocarbon/ring Rings and Amineor Imine Groups (N—N systems bound to this macrocyclic ligand, butTridentates, N—N Tetradentates, or N—N they do not coordinate with thestabilized, high Hexadentates) valence metal ion. This ligand and/orattached, uncoordinating hydrocarbon/rings may or may not have halogenor polarizing or water- insolubilizing groups attached. N ValenceStabilizer #6: N(SiR₃)₃, R′N(SiR₃)₂, or R′R″N(SiR₃) for Silylamines andSilazanes, including silylamines; and [RR″Si—NR′]_(x) (x = 1-10) forMacrocyclic Derivatives, wherein at least silazanes where R, R′, and R″represents H or one Nitrogen Atom is a Binding Site (N any organicfunctional group wherein the Monodentates, N—N Bidentates, N—N number ofcarbon atoms ranges from 0 to 35, Tridentates, N—N Tetradentates, andN—N optionally having halogen or polarizing or Hexadentates)water-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, As, O, S, or Se atoms. N Valence Stabilizer #7:RR′—N—C(═NH)NR″R″′, where R, R′, R″, and Guanidines, Diguanidines, andR″′ represent H or any organic functional group Polyguanidines (N—NBidentates, N—N wherein the number of carbon atoms ranges Tridentates,N—N Tetradentates, and N—N from 0 to 40, optionally having halogen orHexadentates) polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #8: RR′—N—P(═N)—N—R″R″′, where R, R′, R″, andPhosphonitrile Amides, and R″′ represent H or any organic functionalgroup Bis(phosphonitrile amides) (N—N wherein the number of carbon atomsranges Bidentates, N—N Tetradentates) from 0 to 40, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #9: (NH═)PR″″(—NRR′)(—NR″R″′), where R, R′,Phosphonimidic Diamides, R″, R″′, and R″″ represent H or any organicBis(Phosphonimidic Diamides), and functional group wherein the number ofcarbon Poly(Phosphonimidic Diamides) (N—N atoms ranges from 0 to 40,optionally having Bidentates, N—N Tetradentates) halogen or polarizingor water- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #10:(NH═)PR″′(—NRR′)(—OR″) for Phosphonamidimidic Acid, phosphonamidimidicacid and (NH═)PR″′(— Phosphonamidimidothioic Acid, NRR′)(—SR″) forphosphonamidimidothioic Bis(Phosphonamidimidic Acid), acid, where R, R′,R″, and R″′ represent H or Bis(Phosphonamidimidothioic Acid), anyorganic functional group wherein the Poly(Phosphonamidimidic Acid),number of carbon atoms ranges from 0 to 40, Poly(PhosphonamidimidothioicAcid), and optionally having halogen or polarizing or derivativesthereof (N—N Bidentates, and N—N water-insolubilizing/solubilizinggroups Tetradentates) attached. Ligand can also contain nonbinding N, O,S, or P atoms. N Valence Stabilizer #11: C₅H₅N—CR═NR′, where C₅H₅N is apyridine Pyridinaldimines, Bis(pyridinaldimines), derivative, R istypically an aromatic constituent and Poly(pyridinaldimines) (N—N (i.e.,—C₆H₅), and R′ represents H or any organic Bidentates, N—N Tridentates,and N—N functional group wherein the number of carbon Tetradentates)atoms ranges from 0 to 40, optionally having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #12:R—NH—N═R′, where R and R′ represent H or Hydrazones, Bis(hydrazones),and any organic functional group wherein the Poly(hydrazones) (NMonodentates, N—N number of carbon atoms ranges from 0 to 40,Bidentates, N—N Tridentates, and N—N optionally having halogen orpolarizing or Tetradentates) water-insolubilizing/solubilizing groupsattached. (Either R or R′ is typically an aryl group.) Ligand can alsocontain nonbinding N, O, S, or P atoms. N Valence Stabilizer #13:R—N═N—R′ for azo compounds, R—N═N—NH—R′ Azo compounds includingtriazenes without for triazenes, where R, and R′ represent H or chelatesubstitution at the ortho- (for aryl) any organic functional groupwherein the or alpha- or beta- (for alkyl) positions, number of carbonatoms ranges from 0 to 40, Bis(azo compounds), or Poly(azo optionallyhaving halogen or polarizing or compounds) (N Monodentates, N—Nwater-insolubilizing/solubilizing groups Bidentates, or N—N—NTridentates) attached. (Not including ortho- chelate substituted arylazo compounds, and alpha- or beta-substituted alkyl azo compounds.)Ligand can also contain nonbinding N, O, S, or P atoms. N ValenceStabilizer #14: R—N═N—CR′═N—NR″R″′, where R, R′, R″, and Formazans,Bis(formazans), and R″′ represent H, or any organic functionalPoly(formazans) without ortho- hydroxy, group wherein the number ofcarbon atoms carboxy, thiol, mercapto, amino, or ranges from 0 to 40,optionally having halogen hydrazido substitution (N—N Bidentates, N—N orpolarizing or water- Tetradentates, and N—N Hexadentates)insolubilizing/solubilizing groups attached. (Not including ortho-hydroxy, carboxy, thiol, mercapto, amino, or hydrazido substitution.)Ligand can also contain nonbinding N, O, S, or P atoms. N ValenceStabilizer #15: R—CH═N—CHR′—N═CHR″, where R, R′, and R″ Hydramides (N—NBidentates) represent H, or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. (R, R′,and R″ are typically aryl derivatives.) Ligand can also containnonbinding N, O, S, or P atoms. N Valence Stabilizer #16:RR′C═N—N═CR″R″′ or RR′C═N—NR″R″′ (for Azines (including ketazines),Bis(azines), ketazines), where R, R′, R″, and R″′ represent andPoly(azines) without ortho- hydroxy, H, or any organic functional groupwherein the carboxy, thiol, mercapto, amino, or number of carbon atomsranges from 0 to 40, hydrazido substitution (N—N Bidentates, N—Noptionally having halogen or polarizing or Tetradentates, and N—NHexadentates) water-insolubilizing/solubilizing groups attached. (Notincluding ortho- hydroxy, carboxy, thiol, mercapto, amino, or hydrazidosubstitution.) Ligand can also contain nonbinding N, O, S, or P atoms. NValence Stabilizer #17: RR′C═N—R″, where R, R′, and R″ represent H,Schiff Bases with one Imine (C═N) Group or any organic functional groupwherein the and without ortho- (for aryl constituents) or number ofcarbon atoms ranges from 0 to 40, alpha- or beta- (for alkylconstituents) optionally having halogen or polarizing or hydroxy,carboxy, carbonyl, thiol, water-insolubilizing/solubilizing groupsmercapto, thiocarbonyl, amino, imino, attached. (Not including ortho-,alpha-, or beta- oximo, diazeno, or hydrazido substitution hydroxy,carboxy, carbonyl, thiol, mercapto, (N Monodentates) thiocarbonyl,amino, imino, oximo, diazeno, or hydrazido substitution.) Ligand canalso contain nonbinding N, O, S, or P atoms. N Valence Stabilizer #18:Isocyanides, cyanamides, and related ligands Isocyanide and Cyanamideand related where the nitrogen atom is directly complexed ligands (NMonodentates) to the high valence metal ion. N Valence Stabilizer #19:Nitrosyl, nitrite, and related ligands where the Nitrosyl and Nitriteand related ligands (N nitrogen atom is bound directly to the highMonodentates) valence metal ion. N Valence Stabilizer #20: R—CN,R—(CN)₂, R—(CN)_(x), etc. where R Nitriles, Dinitriles, and Polynitriles(N represents H or any organic functional group Monodentates, N—NBidentates, and N—N—N wherein the number of carbon atoms rangesTridentates) from 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. N Valence Stabilizer#21: Azide (—N₃) ligands bound directly to the high Azide ligands (NMonodentates, or N—N valence metal ion. Also includes organoazideBidentates) derivatives (R—N₃), triazenido compounds (R— N₃—R′),phosphonyl azides (R—PO₂H—N₃), phosphoryl azides (O—PO₂H—N3), andsulfonyl azides (R—SO₂—N₃) where R and R′ represent H or any organicfunctional group wherein the number of carbon atoms ranges from 0 to 35,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached S Valence Stabilizer#1: SH₂, SHR, SR₂, where R represents H or any Monothioethers (SMonodentates) wherein organic functional group wherein the number of atleast one Sulfur Atom is a Binding Site carbon atoms ranges from 0 to35, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, P, O, S, or Se atoms. S Valence Stabilizer #2: R—S—S—R′,where R and R′ represents H or any Disulfides (S Monodentates) whereinat organic functional group wherein the number of least one Sulfur Atomis a Binding Site carbon atoms ranges from 0 to 35, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, O, S, or Se atoms. SValence Stabilizer #3: R—S—R′—S—R″, where R, R′, and R″ represents HDithioethers (S—S Bidentates) wherein at or any organic functional groupwherein the least one Sulfur Atom is a Binding Site number of carbonatoms ranges from 0 to 35, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, O, S, or Se atoms. S Valence Stabilizer #4:R—S—R′—S—R″—S—R″′, where R, R′, R″, and R″′ Trithioethers (S—SBidentates or S—S represents H or any organic functional groupTridentates) wherein at least one Sulfur wherein the number of carbonatoms ranges Atom is a Binding Site from 0 to 35, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, O, S, or Se atoms. SValence Stabilizer #5: R—S—R′—S—R″—S—R″′—S—R″″, where R, R′, R″,Tetrathioethers (S—S Bidentates, S—S R″′, and R″″ represents H or anyorganic Tridentates, or S—S Bidentates) wherein at functional groupwherein the number of carbon least one Sulfur Atom is a Binding Siteatoms ranges from 0 to 35, optionally having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, O, S, or Se atoms. S Valence Stabilizer #6:R—S—R′—S—R″—S—R″′—S—R″″—S—R″″′—S—R″″″, Hexathioethers (S—S Bidentates,S—S where R, R′, R″, R″′, R″″, R″″′, and R″″″ Tridentates, S—STetradentates, or S—S represents H or any organic functional groupHexadentates) wherein at least one Sulfur wherein the number of carbonatoms ranges Atom is a Binding Site from 0 to 35, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, O, S, or Se atoms. SValence Stabilizer #7: Five membered heterocyclic ring containing oneFive-Membered Heterocyclic Rings or two sulfur atoms, both of which mayfunction containing One or Two Sulfur Atoms as binding sites. Caninclude other ring systems wherein at least one Sulfur Atom is a boundto this heterocyclic ring, but they do not Binding Site (S Monodentatesor S—S coordinate with the stabilized, high valence Bidentates) metalion. Ring can also contain O, N, P, As, or Se atoms. This 5-memberedring and/or attached, uncoordinating rings may or may not have halogenor polarizing or water- insolubilizing/solubilizing groups attached. SValence Stabilizer #8: Six membered heterocyclic ring containing justSix-Membered Heterocyclic Rings one or two sulfur atoms, both of whichmay containing One or Two Sulfur Atoms function as binding sites. Caninclude other wherein at least one Sulfur Atom is a ring systems boundto this heterocyclic ring, but Binding Site (S Monodentates or S—S theydo not coordinate with the stabilized, high Bidentates) valence metalion. Ring can also contain O, N, P, As, or Se atoms. This 5-memberedring and/or attached, uncoordinating rings may or may not have halogenor polarizing or water- insolubilizing/solubilizing groups attached. SValence Stabilizer #9: Five membered heterocyclic ring(s) containingFive-Membered Heterocyclic Rings one or two sulfur atoms. In addition,ligand containing One or Two Sulfur Atoms at contains additionalsulfur-containing least one additional Sulfur Atom Binding substituents(usually thiols or thioethers) that Site not in a Ring (S Monodentates,S—S constitute S binding sites. Can include other Bidentates, S—STridentates, S—S ring systems bound to the heterocyclic ring or toTetradentates, or S—S Hexadentates) the S-containing substituent, butthey do not coordinate with the stabilized, high valence metal ion.Ring(s) can also contain O, N, P, As or Se atoms. This 5-memberedring(s) and/or attached, uncoordinating rings and/or S- containingsubstituent(s) may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. S Valence Stabilizer #10:Six membered heterocyclic ring(s) containing Six-Membered HeterocyclicRings one or two sulfur atoms. In addition, ligand containing One or TwoSulfur Atoms at contains additional sulfur-containing least oneadditional Sulfur Atom Binding substituents (usually thiols orthioethers) that Site not in a Ring (S Monodentates, S—S constitute Sbinding sites. Can include other Bidentates, S—S Tridentates, S—S ringsystems bound to the heterocyclic ring or to Tetradentates, or S—SHexadentates) the S-containing substituent, but they do not coordinatewith the stabilized, high valence metal ion. Ring(s) can also contain O,N, P, As or Se atoms. This 6-membered ring(s) and/or attached,uncoordinating rings and/or S- containing substituent(s) may or may nothave halogen or polarizing or water- insolubilizing/solubilizing groupsattached. S Valence Stabilizer #11: Five membered heterocyclic ring(s)containing Five-Membered Heterocyclic Rings one or two sulfur atoms. Inaddition, ligand containing One or Two Sulfur Atoms at containsadditional sulfur-containing rings that least one additional Sulfur AtomBinding constitute S binding sites. Can include other Site in a separateRing (S Monodentates, S—S ring systems bound to the S-containingBidentates, S—S Tridentates, S—S heterocyclic rings, but they do notcoordinate Tetradentates, or S—S Hexadentates) with the stabilized, highvalence metal ion. Ring(s) can also contain O, N, P, As, or Se atoms.This 5-membered ring(s) and/or additional S-containing ring(s) and/orattached, uncoordinating rings may or may not have halogen or polarizingor water- insolubilizing/solubilizing groups attached. S ValenceStabilizer #12: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one or two sulfur atoms. In addition,ligand containing One or Two Sulfur Atoms at contains additionalsulfur-containing rings that least one additional Sulfur Atom Bindingconstitute S binding sites. Can include other Site in a separate Ring (SMonodentates, S—S ring systems bound to the S-containing Bidentates, S—STridentates, S—S heterocyclic rings, but they do not coordinateTetradentates, or S—S Hexadentates) with the stabilized, high valencemetal ion. Ring(s) can also contain O, N, P, As, or Se atoms. This6-membered ring(s) and/or additional S-containing ring(s) and/orattached, uncoordinating rings may or may not have halogen or polarizingor water- insolubilizing/solubilizing groups attached. S ValenceStabilizer #13: Macrocyclic ligands containing two to ten sulfur Two-,Three-, Four-, Five-, Six-, Seven-, binding sites to valence stabilizethe central Eight-, Nine-, and Ten-Membered metal ion. Can include otherhydrocarbon or Macrocyclics, Macrobicyclics, and ring systems bound tothis macrocyclic ligand, Macropolycyclics (including Catapinands, butthey do not coordinate with the stabilized, Cryptands, Cyclidenes, andSepulchrates) high valence metal ion. This ligand and/or wherein allBinding Sites are composed of attached, uncoordinatinghydrocarbons/rings Sulfur (usually thiol or thioether groups) may or maynot have halogen or polarizing or and are not contained in Componentwater-insolubilizing/solubilizing groups Heterocyclic Rings (S—SBidentates, S—S attached. Tridentates, S—S Tetradentates, and S—SHexadentates) S Valence Stabilizer #14: Macrocyclic ligands containing atotal of four to Four-, Five-, Six-, Seven-, Eight-, Nine-, or tenfive-membered heterocyclic rings containing Ten-Membered Macrocyclics,sulfur binding sites. Can include other Macrobicyclics, andMacropolycyclics hydrocarbon/ring systems bound to this (includingCatapinands, Cryptands, macrocyclic ligand, but they do not coordinateCyclidenes, and Sepulchrates) wherein all with the stabilized, highvalence metal ion. This Binding Sites are composed of Sulfur and ligandand/or attached, uncoordinating are contained in Component 5-Memberedhydrocarbon/rings may or may not have halogen Heterocyclic Rings (S—STridentates, S—S or polarizing or water-insolubilizing groupsTetradentates or S—S Hexadentates) attached. S Valence Stabilizer #15:Macrocyclic ligands containing at least one 5- Four-, Five-, Six-,Seven-, Eight-, Nine-, or membered heterocyclic ring. These Ten-MemberedMacrocyclics, heterocyclic rings provide sulfur binding sites toMacrobicyclics, and Macropolycyclics valence stabilize the central metalion. Other (including Catapinands, Cryptands, thiol, thioether, orthioketo binding sites can Cyclidenes, and Sepulchrates) wherein allalso be included in the macrocyclic ligand, so Binding Sites arecomposed of Sulfur and long as the total number of binding sites is fourare contained in a Combination of 5- to ten. Can include otherhydrocarbon/ring Membered Heterocyclic Rings and Thiol, systems bound tothis macrocyclic ligand, but Thioether, or Thioketo Groups (S—S they donot coordinate with the stabilized, high Tridentates, S—S Tetradentates,or S—S valence metal ion. This ligand and/or attached, Hexadentates)uncoordinating hydrocarbon/rings may or may not have halogen orpolarizing or water- insolubilizing groups attached. S ValenceStabilizer #16: Macrocyclic ligands containing a total of four to Four-,Five-, Six-, Seven-, Eight-, Nine-, or ten six-membered heterocyclicrings containing Ten-Membered Macrocyclics, sulfur binding sites. Caninclude other Macrobicyclics, and Macropolycyclics hydrocarbon/ringsystems bound to this (including Catapinands, Cryptands, macrocyclicligand, but they do not coordinate Cyclidenes, and Sepulchrates) whereinall with the stabilized, high valence metal ion. This Binding Sites arecomposed of Sulfur and ligand and/or attached, uncoordinating arecontained in Component 6-Membered hydrocarbon/rings may or may not havehalogen Heterocyclic Rings (S—S Tridentates, S—S or polarizing orwater-insolubilizing groups Tetradentates, or S—S Hexadentates)attached. S Valence Stabilizer #17: Macrocyclic ligands containing atleast one 6- Four-, Five-, Six-, Seven-, Eight-, Nine-, or memberedheterocyclic ring. These Ten-Membered Macrocyclics, heterocyclic ringsprovide sulfur binding sites to Macrobicyclics, and Macropolycyclicsvalence stabilize the central metal ion. Other (including Catapinands,Cryptands, thiol, thioether, or thioketo binding sites can Cyclidenes,and Sepulchrates) wherein all also be included in the macrocyclicligand, so Binding Sites are composed of Sulfur and long as the totalnumber of binding sites is four are contained in a Combination of 6- toten. Can include other hydrocarbon/ring Membered Heterocyclic Rings andThiol, systems bound to this macrocyclic ligand, but Thioether, orThioketo Groups (S—S they do not coordinate with the stabilized, highTridentates, S—S Tetradentates, or S—S valence metal ion. This ligandand/or attached, Hexadentates) uncoordinating hydrocarbon/rings may ormay not have halogen or polarizing or water- insolubilizing groupsattached. S Valence Stabilizer #18: RR′—N—C(═S)—NR″—C(═S)—NR″′R″″ forDithiobiurets (Dithioimidodicarbonic dithiobiurets, andRR′—N—C(═S)—NR″—NH— Diamides), Dithioisobiurets, Dithiobiureas,C(═S)—NR″′R″″ for dithiobiureas, where R, R′, Trithiotriurets,Trithiotriureas, R″, R″′, and R″″ represent H, NH₂, or anyBis(dithiobiurets), Bis(dithioisobiurets), organic functional groupwherein the number of Bis(dithiobiureas), Poly(dithiobiurets), carbonatoms ranges from 0 to 40, optionally Poly(dithioisobiurets), and havinghalogen or polarizing or water- Poly(dithiobiureas) (S—S Bidentates, S—Sinsolubilizing/solubilizing groups attached. Tridentates, S—STetradentates) Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #19: RR′—N—C(═S)—NR″—C(═S)—R″′ where R, R′, R″,Thioacylthioureas, Thioaroylthioureas, and R″′ represent H, NH₂, or anyorganic Bis(thioacylthioureas), functional group wherein the number ofcarbon Bis(thioaroylthioureas), atoms ranges from 0 to 40, optionallyhaving Poly(thioacylthioureas), and halogen or polarizing or water-Poly(thioaroylthioureas) (S—S Bidentates, S—Sinsolubilizing/solubilizing groups attached. Tridentates, S—STetradentates) Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #20: R—C(═S)—S—S—C(═S)—R′ where R, and R′ Dithioacyldisulfides, Bis(dithioacyl represent H or any organic functional groupdisulfides), and Poly(dithioacyl disulfides) wherein the number ofcarbon atoms ranges (S—S Bidentates, S—S Tridentates, S—S from 0 to 40,optionally having halogen or Tetradentates) polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #21:RR′—N—C(═S)—S—S—C(═S)—N—R″R″′ where R, R′, TetrathioperoxydicarbonicDiamides, R″, R″′ represent H or any organic functionalBis(tetrathioperoxydicarbonic diamides), group wherein the number ofcarbon atoms and poly(tetrathioperoxydicarbonic ranges from 0 to 40,optionally having halogen diamides) (S—S Bidentates, S—S Tridentates, orpolarizing or water- S—S Tetradentates) insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S Valence Stabilizer #22: R—S—C(═S)—S—S—C(═S)—S—R′ for Hexathio-,Pentathio-, and hexathioperoxydicarbonic acids, R—O—C(═S)—S—Tetrathioperoxydicarbonic Acids, S—C(═S)—S—R′ forpentathioperoxydicarbonic Bis(hexathio-, pentathio-, and acids, andR—O—C(═S)—S—S—C(═S)—O—R′ for tetrathioperoxydicarbonic acids),tetrathioperoxydicarbonic acids, where R and R′ poly(hexathio-,pentathio-, and represent H, NH₂ or any organic functionaltetrathioperoxydicarbonic acids), and group wherein the number of carbonatoms derivatives thereof (S—S Bidentates, S—S ranges from 0 to 40,optionally having halogen Tridentates, S—S Tetradentates) or polarizingor water- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #23:(RR′—N—)(R″R″′—N—)P(═S)—S—S—P(═S)(—N— Dithioperoxydiphosphoramide,R″″R″″′)(—N—R″″″R″″″′), where R, R′, R″, R″′,Bis(dithioperoxyphosphoramide), and R″″, R″″′, R″″″, and R″″″′ representH, NH₂ or Poly(dithioperoxydiphosphoramide) (S—S any organic functionalgroup wherein the Bidentates, S—S Tridentates, S—S number of carbonatoms ranges from 0 to 40, Tetradentates) optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#24: (R—O—)(R′—O—)P(═S)—S—S—P(═S)(—O—R″)(—O— DithioperoxydiphosphoricAcids, R″′); (R—O—)(R′—S—)P(═S)—S—S—P(═S)(—S—R″)(—O—Bis(dithioperoxyphosphoric Acids), R″′); or(R—S—)(R′—S—)P(═S)—S—S—P(═S)(—S—R″) Poly(dithioperoxydiphosphoricAcids), and (—S—R″′), where R, R′, R″, R″′, R″″, R″″′, R″″″, derivativesthereof (S—S Bidentates, S—S and R″″″′ represent H, NH₂ or any organicTridentates, S—S Tetradentates) functional group wherein the number ofcarbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#25: (R—O—)(R′—)P(═S)—NH—P(═S)(—R″)(—O—R″′); (R— DithioimidodiphosphonicAcids, S—)(R′—)P(═S)—NH—P(═S)(—R″)(—O—R″′); or (R—Dithiohydrazidodiphosphonic Acids, S—)(R′—)P(═S)—NH—P(═S)(—R″)(—S—R″′)for Bis(dithioimidodiphosphonic acids), dithioimidodiphosphonic acids,and —NH—NH— Bis(dithiohydrazidodiphosphonic acids), derivatives fordithiohydrazidodiphosphonic Poly(dithioimidodiphosphonic acids), acids,where R, R′, R″, and R″′ represent H, Poly(dithiohydrazidodiphosphonicacids), NH₂ or any organic functional group wherein and derivativesthereof (S—S Bidentates, S—S the number of carbon atoms ranges from 0 toTridentates, and S—S Tetradentates) 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#26: (RR′—N—)(R″—)P(═S)—NH—P(═S)(—R″′)(—N— Dithioimidodiphosphonamides,R″″R″″′) for dithioimidophosphonamides, andDithiohydrazidodiphosphonamides,(RR′—N—)(R″—)P(═S)—NH—NH—P(═S)(—R″′)(—N—Bis(dithioimidodiphosphonamides), R″″R″″′) forBis(dithiohydrazidodiphosphonamides), dithiohydrazidodiphosphonamides,where R, R′, Poly(dithioimidodiphosphonamides), and R″, R″′, R″″, andR″″′ represent H, NH₂ or any Poly(dithiohydrazidodiphosphonamides)organic functional group wherein the number of (S—S Bidentates, S—STridentates, S—S carbon atoms ranges from 0 to 40, optionallyTetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #27:(RR′—N—)(R″—)P(═S)—S—P(═S)(—R″′)(—N— Dithiodiphosphonamides, R″″R″″′),or (RR′—N—)(R″—)P(═S)—O—P(═S) Bis(dithiophosphonamides), and(—R″′)(—N—R″″R″″′), where R, R′, R″, R″′, R″″,Poly(dithiodiphosphonamides) (S—S and R″″′ represent H, NH₂ or anyorganic Bidentates, S—S Tridentates, S—S functional group wherein thenumber of carbon Tetradentates) atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S Valence Stabilizer #28: (R—O—)(R′—)P(═S)—O—P(═S)(—R″)(—O—R″′);Dithiodiphosphonic Acids, (R—O—)(R′—)P(═S)—S—P(═S)(—R″)(—O—R″′);Bis(dithioiphosphonic Acids), (R—S—)(R′—)P(═S)—O—P(═S)(—R″)(—S—R″′);Poly(dithiodiphosphonic Acids), and or(R—S—)(R′—)P(═S)—S—P(═S)(—R″)(—S—R″′); derivatives thereof (S—SBidentates, S—S where R, R′, R″, and R″′ represent H, NH₂ or any organicTridentates, S—S Tetradentates) functional group wherein the number ofcarbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#29: (RR′—N—)(R″—)P(═S)—S—S—P(═S)(—R″′)(—N— Dithioperoxydiphosphonamide,R″″R″″′), where R, R′, R″, R″′, R″″, and R″″′Bis(dithioperoxyphosphonamide), and represent H, NH₂ or any organicfunctional Poly(dithioperoxydiphosphonamide) (S—S group wherein thenumber of carbon atoms Bidentates, S—S Tridentates, S—S ranges from 0 to40, optionally having halogen Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #30:(R—O—)(R′—)P(═S)—S—S—P(═S)(—R″)(—O—R″′); or DithioperoxydiphosphonicAcids, (R—S—)(R′—)P(═S)—S—S—P(═S)(—R″)(—S—R″′),Bis(dithioperoxyphosphonic Acids), where R, R′, R″, and R″′ represent H,NH₂ or Poly(dithioperoxydiphosphonic Acids), and any organic functionalgroup wherein the derivatives thereof (S—S Bidentates, S—S number ofcarbon atoms ranges from 0 to 40, Tridentates, S—S Tetradentates)optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #31:(O═)PR(—S—R′)(—S—R″) or (S═)PR(—S—R′)(—O— Dithiophosphonic Acids R″),where R, R′, and R″ represent H, NH₂ or (Phosphonodithioic Acids), anyorganic functional group wherein the Bis(dithiophosphonic Acids), numberof carbon atoms ranges from 0 to 40, Poly(dithiophosphonic Acids), andoptionally having halogen or polarizing or derivatives thereof (S—SBidentates, S—S water-insolubilizing/solubilizing groups Tridentates,S—S Tetradentates) attached. Ligand can also contain nonbinding N, O, S,or P atoms. S Valence Stabilizer #32: (S═)PR(—S—R′)(—S—R″), where R, R′,and R″ Trithiophosphonic Acids represent H, NH₂ or any organicfunctional (Phosphonotrithioic Acids), group wherein the number ofcarbon atoms Bis(trithiophosphonic Acids), ranges from 0 to 40,optionally having halogen Poly(trithiophosphonic Acids), and orpolarizing or water- derivatives thereof (S—S Bidentates, S—Sinsolubilizing/solubilizing groups attached. Tridentates, S—STetradentates) Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #33: (O═)PR(—S—S—R′)(—S—R″) or (S═)PR(—S—S—R′)Phosphono(dithioperoxo)thioic Acids), (—O—R″), where R, R′, and R″represent H, NH₂ or Bis[phosphono(dithioperoxo)thioic Acids], anyorganic functional group wherein the Poly[phosphono(dithioperoxo)thioicnumber of carbon atoms ranges from 0 to 40, Acids], and derivativesthereof (S—S optionally having halogen or polarizing or Bidentates, S—STridentates, S—S water-insolubilizing/solubilizing groups Tetradentates)attached. Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #34: (S═)PR(—S—S—R′)(—S—R″), where R, R′, and R″Phosphono(dithioperoxo)dithioic Acids), represent H, NH₂ or any organicfunctional Bis[phosphono(dithioperoxo)dithioic group wherein the numberof carbon atoms Acids], ranges from 0 to 40, optionally having halogenPoly[phosphono(dithioperoxo)dithioic or polarizing or water- Acids], andderivatives thereof (S—S insolubilizing/solubilizing groups attached.Bidentates, S—S Tridentates, S—S Ligand can also contain nonbinding N,O, S, or Tetradentates) P atoms. S Valence Stabilizer #35: R—S—R′CSOH orR—S—R′CSSH for S- S-(Alkylthio)thiocarboxylic Acids, S-(alkylthio)thiocarboxylic and S- (Arylthio)thiocarboxylic Acids, andS,S- (arylthio)thiocarboxylic acids, and thiobisthiocarboxylic Acids(S—S Bidentates HSOCR—S—R′COSH or HSSCR—S—R′CSSH for and S—STridentates) S,S-thiobisthiocarboxylic acids, where R and R′ represent Hor any organic functional group wherein the number of carbon atomsranges from 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #36:R—S—S—R′CSOH or R—S—S—R′CSSH for S- S-(Alkyldisulfido)thiocarboxylicAcids, S- (alkyldisulfido)thiocarboxylic and S-(Aryldisulfido)thiocarboxylic Acids, and (aryldisulfido)thiocarboxylicacids, and S,S′-Disulfidobisthiocarboxylic Acids (S—S HSOCR—S—S—R′COSHor HSSCR—S—S—R′CSSH Bidentates and S—S Tridentates) forS,S′-disulfidobisthiocarboxylic acids, where R and R′ represent H or anyorganic functional group wherein the number of carbon atoms ranges from0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #37:R—CH(—SR″)—CH(—SR″′)—R′, and 1,2-Dithiolates, Bis(1,2-dithiolates), andR—C(—SR″)═C(—SR″′)—R′, where R, R′, R″, and Poly(1,2-dithiolates) (S—SBidentates, S—S R″′ represent H, NH₂ or any organic functionalTridentates, S—S Tetradentates) group wherein the number of carbon atomsranges from 0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #38:RN—C(═O)—CHR′—S—C(═S) for rhodanines, and Rhodanines and Bis(rhodanines)(S—S R—[N—C(═O)—CHR′—S—C(═S)]₂ for Bidentates and S—S Tetradentates)bis(rhodanines), where R and R′ represent H, NH₂ or any organicfunctional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #39:RN═C(SH)(SH), where R represents H, NH₂ or Dithiocarbimates,Bis(dithiocarbimates), any organic functional group wherein the andPoly(dithiocarbimates) (S—S Bidentates, number of carbon atoms rangesfrom 0 to 40, S—S Tridentates, and S—S Tetradentates) optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #40: RS⁺═C(SH)(SH) or RS—C(═S)(SH), where RThioxanthates, Bis(thioxanthates), and represents H, NH₂ or any organicfunctional Poly(thioxanthates) (S—S Bidentates and S—S group wherein thenumber of carbon atoms Tetradentates) ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S Valence Stabilizer #41: RO⁺═C(SH)(SH) or RO—C(═S)(SH), where RXanthates, Bis(xanthates), and represents H, NH₂ or any organicfunctional Poly(xanthates) (S—S Bidentates and S—S group wherein thenumber of carbon atoms Tetradentates) ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S Valence Stabilizer #42: Typically RR′R″P═C(SH)(SH) [pentavalent P],Phosphinodithioformates (S—S Bidentates) although RR′P—C(═S)(SH)[trivalent P] may be acceptable in some situations, where R, R′, and R″represent H, NH₂ or any organic functional group wherein the number ofcarbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#43: R—S—C(—S—R″)—O—R′ for dithioborates, R—S—C(—S— Alkyl- andAryl-Dithioborates, R″)—S—R′ for trithioborates, and R—S—S—C(—S—Trithioborates, Perthioborates, R″)—S—R′ for perthioborates, where R,R′, and Bis(dithioborates), Bis(trithioborates), and R″ represent H, NH₂or any organic functional Bis(perthioborates) (S—S Bidentates and S—Sgroup wherein the number of carbon atoms Tetradentates) ranges from 0 to40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #44:R—C(—S—R″)—S—R′, where R, R′, and R″ Alkyl- and Aryl-Dithioboronates,and represent H, NH₂ or any organic functional Bis(dithioboronates) (S—SBidentates and S—S group wherein the number of carbon atomsTetradentates) ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S Valence Stabilizer#45: (O═)As(—S—R)(—S—R′)(—S—R″) or (S═)As(—S—R) Trithioarsonic Acids(Arsonotrithioic (—S—R′)(—O—R″) for trithioarsonic acid; (O═)As(—O—R)Acids), Dithioarsonic Acids (—S—R′)(—S—R″) or (S═)As(—S—R)(—O—R′)(Arsonodithioic Acids), Tetrathioarsonic (—O—R″) for dithioarsonic acid,or (S═)As(—S—R)(—S—R′) Acids (Arsonotetrathioic Acids), and (—S—R″) fortetrathioarsonic acid, where R, derivatives thereof (S—S Bidentates, S—SR′, and R″ represent H, NH₂ or any organic Tridentates, S—STetradentates) functional group wherein the number of carbon atomsranges from 0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S Valence Stabilizer #46:(O═)Sb(—S—R)(—S—R′)(—S—R″) or Trithioantimonic Acids (Stibonotrithioic(S═)Sb(—S—R)(—S—R′)(—O—R″) for trithioantimonic acid; Acids),Dithioantimonic Acids (O═)Sb(—O—R)(—S—R′)(—S—R″) or (StibonodithioicAcids), Tetrathioantimonic (S═)Sb(—S—R)(—O—R′)(—O—R″) fordithioantimonic Acids (Stibonotetrathioic Acids), and acid, or(S═)Sb(—S—R)(—S—R′)(—S—R″) for derivatives thereof (S—S Bidentates, S—Stetrathioantimonic acid, where R, R′, and R″ Tridentates, S—STetradentates) represent H, NH₂ or any organic functional group whereinthe number of carbon atoms ranges from 0 to 40, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #47: RR′R″P═S for phosphine P-sulfides, and PhosphineP-sulfides and Amino- (RR′N)(R″R″′N)(R″″R″″′N)P═S for amino- substitutedPhosphine sulfides (S substituted phosphine sulfides, where R, R′, R″,Monodentates) R″′, R″″, and R″″′ represent H, Cl, Br, NH₂ or any organicfunctional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. (Rs are typicallyaromatic or heterocyclic for phosphine P-sulfides.) Ligand can alsocontain nonbinding N, O, S, or P atoms. S Valence Stabilizer #48:RR′R″As═S for arsine As-sulfides, and Arsine As-sulfides andAmino-substituted (RR′N)(R″R″′N)(R″″R″″′N)As═S for amino- Arsinesulfides (S Monodentates) substituted arsine sulfides, where R, R′, R″,R″′, R″″, and R″″′ represent H, Cl, Br, NH₂ or any organic functionalgroup wherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water-insolubilizing/solubilizing groupsattached. (Rs are typically aromatic or heterocyclic for arsineAs-sulfides.) Ligand can also contain nonbinding N, O, S, or P atoms. SValence Stabilizer #49: Thiols (HS—R, HS—R—SH, etc.), where R and R′Thiolates (S Monodentates) represent H or any organic functional groupwherein the number of carbon atoms ranges from 0 to 35, optionallyhaving halogen or polarizing or water-insolubilizing/solubilizing groupsattached. S Valence Stabilizer #50: Sulfide (—S²⁻) ligands bounddirectly to the high Sulfide ligands (S Monodentates) valence metal ion.P Valence Stabilizer #1: PH₃, PH₂R, PHR₂, and PR₃ where R representsMonophosphines (P Monodentates) H or any organic functional groupwherein the wherein at least one Phosphorus Atom is a number of carbonatoms ranges from 0 to 35, Binding Site optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, P, As, O, S, or Se atoms. P ValenceStabilizer #2: R′—P—R—P—R″, where R, R′, and R″ represent H Diphosphines(a P—P Bidentate) wherein at or any organic functional group wherein theleast one Phosphorus Atom is a Binding number of carbon atoms rangesfrom 0 to 35, Site optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, As, O, S, or Se atoms. P Valence Stabilizer #3:R—P—R′—P—R″—P—R″′, where R, R′, R″, and R″′ Triphosphines (either P—PBidentates or P— represent H or any organic functional group P—PTridentates) wherein at least one wherein the number of carbon atomsranges Phosphorus Atom is a Binding Site from 0 to 35, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, As, O, S, or Seatoms. P Valence Stabilizer #4: R—P—R′—P—R″—P—R″′—P—R″″, where R, R′,R″, Tetraphosphines (P—P Bidentates, P—P R″′, and R″″ represent H or anyorganic Tridentates, or P—P Tetradentates) wherein functional groupwherein the number of carbon at least one Phosphorus Atom is a Bindingatoms ranges from 0 to 35, optionally having Site halogen or polarizingor water- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, As, O, S, or Se atoms. P Valence Stabilizer #5:R—P—R′—P—R″—P—R″′—P—R″″—P—R″″′, where R, R′, Pentaphosphines (P—PBidentates, P—P R″, R″′, R″″, and R″″′ represent H or any Tridentates,or P—P Tetradentates) wherein organic functional group wherein thenumber of at least one Phosphorus Atom is a Binding carbon atoms rangesfrom 0 to 35, optionally Site having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, P, As, O, S, or Se atoms. P Valence Stabilizer #6:R—P—R′—P—R″—P—R″′—P—R″″—P—R″″′—P—R″″″, Hexaphosphines (P—P Bidentates,P—P where R, R′, R″, R″′, R″″, R″″′, and R″″″ Tridentates, P—PTetradentates, or P—P represent H or any organic functional groupHexadentates) wherein at least one wherein the number of carbon atomsranges Phosphorus Atom is a Binding Site from 0 to 35, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, As, O, S, or Seatoms. P Valence Stabilizer #7: Five membered heterocyclic ringcontaining Five-Membered Heterocyclic Rings one, two, or threephosphorus atoms, all of containing One, Two, or Three Phosphorus whichmay or may not function as binding sites. Atoms wherein at least onePhosphorus Can include other ring systems bound to this Atom is aBinding Site (P Monodentates or heterocyclic ring, but they do notcoordinate P—P Bidentates) with the stabilized, high valence metal ion.Ring can also contain O, S, N, As, or Se atoms. This 5-membered ringand/or attached, uncoordinating rings may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. PValence Stabilizer #8: Six membered heterocyclic ring containing one,Six-Membered Heterocyclic Rings two, or three phosphorus atoms, all ofwhich containing One, Two, or Three Phosphorus may or may not functionas binding sites. Can Atoms wherein at least one Phosphorus includeother ring systems bound to this Atom is a Binding Site (P Monodentatesor heterocyclic ring, but they do not coordinate P—P Bidentates) withthe stabilized, high valence metal ion. Ring can also contain O, S, N,As, or Se atoms. This 6-membered ring and/or attached, uncoordinatingrings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. P Valence Stabilizer #9:Five membered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one, two, or three phosphorus atoms. In containing One, Two, orThree Phosphorus addition, ligand contains additional phosphorus- Atomsat least one additional Phosphorus containing substituents (usuallyphosphines) Atom Binding Site not in a Ring (P that constitute P bindingsites. Can include Monodentates, P—P Bidentates, P—P other ring systemsbound to the heterocyclic Tridentates, P—P Tetradentates, or P—P ring orto the P-containing substituent, but they Hexadentates) do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, N, S, As or Se atoms. This 5-membered ring(s) and/orattached, uncoordinating rings and/or P- containing substituent(s) mayor may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. P Valence Stabilizer #10:Six membered heterocyclic ring(s) containing Six-Membered HeterocyclicRings one, two, or three phosphorus atoms. In containing One, Two, orThree Phosphorus addition, ligand contains additional phosphorus- Atomsat least one additional Phosphorus containing substituents (usuallyphosphines) Atom Binding Site not in a Ring (P that constitute P bindingsites. Can include Monodentates, P—P Bidentates, P—P other ring systemsbound to the heterocyclic Tridentates, P—P Tetradentates, or P—P ring orto the P-containing substituent, but they Hexadentates) do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, N, S, As or Se atoms. This 6-membered ring(s) and/orattached, uncoordinating rings and/or P- containing substituent(s) mayor may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. P Valence Stabilizer #11:Five membered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one, two, or three phosphorus atoms. In containing One, Two, orThree Phosphorus addition, ligand contains additional phosphorus- Atomsat least one additional Phosphorus containing rings that constitute Pbinding sites. Atom Binding Site in a separate Ring (P Can include otherring systems bound to the P- Monodentates, P—P Bidentates, P—Pcontaining heterocyclic rings, but they do not Tridentates, P—PTetradentates, or P—P coordinate with the stabilized, high valenceHexadentates) metal ion. Ring(s) can also contain O, N, S, As, or Seatoms. This 5-membered ring(s) and/or additional P-containing ring(s)and/or attached, uncoordinating rings may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. PValence Stabilizer #12: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one, two, or three phosphorus atoms. Incontaining One, Two, or Three Phosphorus addition, ligand containsadditional phosphorus- Atoms at least one additional Phosphoruscontaining rings that constitute P binding sites. Atom Binding Site in aseparate Ring (P Can include other ring systems bound to the P-Monodentates, P—P Bidentates, P—P containing heterocyclic rings, butthey do not Tridentates, P—P Tetradentates, or P—P coordinate with thestabilized, high valence Hexadentates) metal ion. Ring(s) can alsocontain O, N, S, As, or Se atoms. This 6-membered ring(s) and/oradditional P-containing ring(s) and/or attached, uncoordinating ringsmay or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. P Valence Stabilizer #13:Macrocyclic ligands containing two, three, four, Two-, Three-, Four-,Five-, Six-, and Eight- five, six, or eight phosphorus binding sites toMembered Macrocyclics, Macrobicyclics, valence stabilize the centralmetal ion. Can and Macropolycyclics (including include other hydrocarbonor ring systems Catapinands, Cryptands, Cyclidenes, and bound to thismacrocyclic ligand, but they do Sepulchrates) wherein all Binding Sitesare not coordinate with the stabilized, high valence composed ofPhosphorus and are not metal ion. This ligand and/or attached, containedin Component Heterocyclic uncoordinating hydrocarbons/rings may or mayRings (P—P Bidentates, P—P Tridentates, P—P not have halogen orpolarizing or water- Tetradentates, and P—P Hexadentates)insolubilizing/solubilizing groups attached. P Valence Stabilizer #14:Macrocyclic ligands containing a total of four, Four-, Six-, orEight-Membered six, or eight five-membered heterocyclic ringsMacrocyclics, Macrobicyclics, and containing phosphorus binding sites.Can Macropolycyclics (including Catapinands, include otherhydrocarbon/ring systems bound Cryptands, Cyclidenes, and Sepulchrates)to this macrocyclic ligand, but they do not wherein all Binding Sitesare composed of coordinate with the stabilized, high valence Phosphorusand are contained in metal ion. This ligand and/or attached, Component5-Membered Heterocyclic uncoordinating hydrocarbon/rings may or mayRings (P—P Tridentates, P—P Tetradentates, not have halogen orpolarizing or water- or P—P Hexadentates) insolubilizing groupsattached. P Valence Stabilizer #15: Macrocyclic ligands containing atleast one 5- Four-, Six-, or Eight-Membered membered heterocyclic ring.These Macrocyclics, Macrobicyclics, and heterocyclic rings providephosphorus binding Macropolycyclics (including Catapinands, sites tovalence stabilize the central metal ion. Cryptands, Cyclidenes, andSepulchrates) Other phosphine binding sites can also be wherein allBinding Sites are composed of included in the macrocyclic ligand, solong as Phosphorus and are contained in a the total number of bindingsites is four, six, or Combination of 5-Membered Heterocyclic eight. Caninclude other hydrocarbon/ring Rings and Phosphine Groups (P—P systemsbound to this macrocyclic ligand, but Tridentates, P—P Tetradentates, orP—P they do not coordinate with the stabilized, high Hexadentates)valence metal ion. This ligand and/or attached, uncoordinatinghydrocarbon/rings may or may not have halogen or polarizing or water-insolubilizing groups attached. P Valence Stabilizer #16: Macrocyclicligands containing a total of four, Four-, Six-, or Eight-Membered six,or eight six-membered heterocyclic rings Macrocyclics, Macrobicyclics,and containing phosphorus binding sites. Can Macropolycyclics (includingCatapinands, include other hydrocarbon/ring systems bound Cryptands,Cyclidenes, and Sepulchrates) to this macrocyclic ligand, but they donot wherein all Binding Sites are composed of coordinate with thestabilized, high valence Phosphorus and are contained in metal ion. Thisligand and/or attached, Component 6-Membered Heterocyclic uncoordinatinghydrocarbon/rings may or may Rings (P—P Tridentates, P—P Tetradentates,not have halogen or polarizing or water- or P—P Hexadentates)insolubilizing groups attached. P Valence Stabilizer #17: Macrocyclicligands containing at least one 6- Four-, Six-, or Eight-Memberedmembered heterocyclic ring. These Macrocyclics, Macrobicyclics, andheterocyclic rings provide phosphorus binding Macropolycyclics(including Catapinands, sites to valence stabilize the central metalion. Cryptands, Cyclidenes, and Sepulchrates) Other phosphine bindingsites can also be wherein all Binding Sites are composed of included inthe macrocyclic ligand, so long as Phosphorus and are contained in a thetotal number of binding sites is four, six, or Combination of 6-MemberedHeterocyclic eight. Can include other hydrocarbon/ring Rings andPhosphine Groups (P—P systems bound to this macrocyclic ligand, butTridentates, P—P Tetradentates, or P—P they do not coordinate with thestabilized, high Hexadentates) valence metal ion. This ligand and/orattached, uncoordinating hydrocarbon/rings may or may not have halogenor polarizing or water- insolubilizing groups attached. O ValenceStabilizer #1: R—O—C(═O)—S—S—C(═O)—O—R′, where R and R′Dithioperoxydicarbonic Acids, represent H, NH₂ or any organic functionalBis(dithioperoxydicarbonic acids), group wherein the number of carbonatoms poly(dithioperoxydicarbonic acids), and ranges from 0 to 40,optionally having halogen derivatives thereof (O—O Bidentates, O—O orpolarizing or water- Tridentates, O—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #2:(R—O—)(R′—)P(═O)—NH—P(═O)(—R″)(—O—R″′) for Imidodiphosphonic Acids,imidodiphosphonic acids, and (R—O—)(R′—) Hydrazidodiphosphonic Acids,P(═O)—NH—NH—P(═O)(—R″)(—O—R″′) for Bis(imidodiphosphonic Acids),hydrazidodiphosphonic acids; where R, R′, R″, Bis(hydrazidodiphosphonicAcids), and R″′ represent H, NH₂ or any organic Poly(imidodiphosphonicAcids), functional group wherein the number of carbonPoly(hydrazidodiphosphonic Acids), and atoms ranges from 0 to 40,optionally having derivatives thereof (O—O Bidentates, O—O halogen orpolarizing or water- Tridentates, O—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #3:(RR′—N—)(R″—)P(═O)—NH—P(═O)(—R″′)(—N— Imidodiphosphonamides, R″″R″″′)for imidodiphosphonamides, and Hydrazidodiphosphonamides, —NH—NH—derivatives for Bis(imidodiphosphonamides), hydrazidodiphosphonamides,where R, R′, R″, Bis(hydrazidodiphosphonamides), R″′, R″″, and R″″′represent H, NH₂ or any Poly(imidodiphosphonamides), and organicfunctional group wherein the number of Poly(hydrazidodiphosphonamides)(O—O carbon atoms ranges from 0 to 40, optionally Bidentates, O—OTridentates, O—O having halogen or polarizing or water- Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #4:(RR′—N—)(R″—)P(═O)—O—P(═O)(—R″′)(—N— Diphosphonamides, R″″R″″′), whereR, R′, R″, R″′, R″″, and R″″′ Bis(diphosphonamides), and represent H,NH₂ or any organic functional Poly(diphosphonamides) (O—O Bidentates,group wherein the number of carbon atoms O—O Tridentates, O—OTetradentates) ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#5: RR′N-NR″—C(═O)(OH), where R and R′ Carbazates (carbazides),Bis(carbazates), represent H, NH₂ or any organic functional andPoly(carbazates) (O—O Bidentates, O—O group wherein the number of carbonatoms Tridentates, and O—O Tetradentates; or ranges from 0 to 40,optionally having halogen possibly N—O Bidentates, N—O Tridentates, orpolarizing or water- and N—O Tetradentates) insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.O Valence Stabilizer #6: (O═)As(—O—R)(—O—R′)(—O—R″), where R, R′, andArsonic Acids, Bis(arsonic acids), R″ represent H, NH₂ or any organicfunctional Poly(arsonic acids), and derivatives thereof group whereinthe number of carbon atoms (O—O Bidentates, O—O Tridentates, O—O rangesfrom 0 to 40, optionally having halogen Tetradentates) or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. O Valence Stabilizer #7:R—O—C(—O—R″)—O—R′, where R, R′, and R″ Alkyl- and Aryl- Borates andBis(borates) represent H, NH₂ or any organic functional (O—O Bidentatesand O—O Tetradentates) group wherein the number of carbon atoms rangesfrom 0 to 40, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #8:R—C(—O—R″)—O—R′, where R, R′, and R″ Alkyl- and Aryl- Boronates andrepresent H, NH₂ or any organic functional Bis(boronates) (O—OBidentates and O—O group wherein the number of carbon atomsTetradentates) ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. O Valence Stabilizer#9: RR′R″P═O for phosphine P-oxides, and Phosphine P-oxides andAmino-substituted (RR′N)(R″R″′N)(R″″R″″′N)P═O for amino- Phosphineoxides (O Monodentates) substituted phosphine oxides, where R, R′, R″,R″′, R″″, and R″″′ represent H, Cl, Br, NH₂ or any organic functionalgroup wherein the number of carbon atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water-insolubilizing/solubilizing groupsattached. (Rs are typically aromatic or heterocyclic for phosphineP-oxides.) Ligand can also contain nonbinding N, O, S, or P atoms. OValence Stabilizer #10: RR′R″As═O for arsine As-oxides, and ArsineAs-oxides and Amino-substituted (RR′N)(R″R″′N)(R″″R″″′N)As═O for amino-Arsine oxides (O Monodentates) substituted arsine oxides, where R, R′,R″, R″′, R″″, and R″″′ represent H, Cl, Br, NH₂ or any organicfunctional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. (Rs are typically aromaticor heterocyclic for arsine As-oxides.) Ligand can also containnonbinding N, O, S, or P atoms. O Valence Stabilizer #11: Five memberedheterocyclic ring containing one Five-Membered Heterocyclic Rings or twooxygen atoms, both of which may or containing One or Two Oxygen Atomsmay not function as binding sites. Can include wherein at least oneOxygen Atom is a other ring systems bound to this heterocyclic BindingSite (O Monodentates or O—O ring, but they do not coordinate with theBidentates) stabilized, high valence metal ion. Ring can also contain O,S, or P atoms. This 5-membered ring and/or attached, uncoordinatingrings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. O Valence Stabilizer #12:Six membered heterocyclic ring containing one Six-Membered HeterocyclicRings or two oxygen atoms, both of which may or containing One or TwoOxygen Atoms may not function as binding sites. Can include wherein atleast one Oxygen Atom is a other ring systems bound to this heterocyclicBinding Site (O Monodentates or O—O ring, but they do not coordinatewith the Bidentates) stabilized, high valence metal ion. Ring can alsocontain O, S, or P atoms. This 6-membered ring and/or attached,uncoordinating rings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. O Valence Stabilizer #13:Five membered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one or two oxygen atoms. In addition, ligand containing One or TwoOxygen Atoms and contains additional oxygen-containing having at leastone additional Oxygen Atom substituents (usually hydroxyl or estergroups) Binding Site not in a Ring (O that constitute O binding sites.Can include Monodentates, O—O Bidentates, O other ring systems bound tothe heterocyclic Tridentates, O Tetradentates, or O ring or to theO-containing substituent, but they Hexadentates) do not coordinate withthe stabilized, high valence metal ion. Ring(s) can also contain O, S,or P atoms. This 5-membered ring(s) and/or attached, uncoordinatingrings and/or O- containing substituent(s) may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. OValence Stabilizer #14: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one or two oxygen atoms. In addition,ligand containing One or Two Oxygen Atoms and contains additionaloxygen-containing having at least one additional Oxygen Atomsubstituents (usually hydroxyl or ester groups) Binding Site not in aRing (O that constitute O binding sites. Can include Monodentates, O—OBidentates, O other ring systems bound to the heterocyclic Tridentates,O Tetradentates, or O ring or to the O-containing substituent, but theyHexadentates) do not coordinate with the stabilized, high valence metalion. Ring(s) can also contain O, S, or P atoms. This 6-membered ring(s)and/or attached, uncoordinating rings and/or O- containingsubstituent(s) may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. O Valence Stabilizer #15:Five membered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one or two oxygen atoms. In addition, ligand containing One or TwoOxygen Atoms and contains additional oxygen-containing rings that havingat least one additional Oxygen Atom constitute O binding sites. Caninclude other Binding Site in a Separate Ring (O ring systems bound tothe O-containing Monodentates, O—O Bidentates, O heterocyclic rings, butthey do not coordinate Tridentates, O Tetradentates, or O with thestabilized, high valence metal ion. Hexadentates) Ring(s) can alsocontain O, S, or P atoms. This 5-membered ring(s) and/or additional O-containing ring(s) and/or attached, uncoordinating rings may or may nothave halogen or polarizing or water- insolubilizing/solubilizing groupsattached. O Valence Stabilizer #16: Six membered heterocyclic ring(s)containing Six-Membered Heterocyclic Rings one or two oxygen atoms. Inaddition, ligand containing One or Two Oxygen Atoms and containsadditional oxygen-containing rings that having at least one additionalOxygen Atom constitute O binding sites. Can include other Binding Sitein a Separate Ring (O ring systems bound to the O-containingMonodentates, O—O Bidentates, O heterocyclic rings, but they do notcoordinate Tridentates, O Tetradentates, or O with the stabilized, highvalence metal ion. Hexadentates) Ring(s) can also contain O, S, or Patoms. This 6-membered ring(s) and/or additional O- containing ring(s)and/or attached, uncoordinating rings may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. OValence Stabilizer #17: Macrocyclic ligands containing four, five, six,Four-, Five-, Six-, Seven-, Eight-, and Ten- seven, eight, or ten oxygenbinding sites to Membered Macrocyclics, Macrobicyclics, valencestabilize the central metal ion. Can and Macropolycyclics (includinginclude other hydrocarbon or ring systems Catapinands, Cryptands,Cyclidenes, and bound to this macrocyclic ligand, but they doSepulchrates) wherein all Binding Sites are not coordinate with thestabilized, high valence composed of Oxygen (usually ester or metal ion.This ligand and/or attached, hydroxyl groups) and are not contained inuncoordinating hydrocarbons/rings may or may Component HeterocyclicRings (O—O not have halogen or polarizing or water- Bidentates, O—OTridentates, O—O insolubilizing/solubilizing groups attached.Tetradentates, and O—O Hexadentates) O Valence Stabilizer #18:Macrocyclic ligands containing a total of four, Four-, Five-, Six-,Seven-, Eight-, and Ten- five, six, seven, eight, or ten five-memberedMembered Macrocyclics, Macrobicyclics, heterocyclic rings containingoxygen binding and Macropolycyclics (including sites. Can include otherhydrocarbon or ring Catapinands, Cryptands, Cyclidenes, and systemsbound to this macrocyclic ligand, but Sepulchrates) wherein all BindingSites are they do not coordinate with the stabilized, high composed ofOxygen and are contained in valence metal ion. This ligand and/orattached, Component 5-Membered Heterocyclic uncoordinatinghydrocarbons/rings may or may Rings (O—O Bidentates, O—O Tridentates,not have halogen or polarizing or water- O—O Tetradentates, and O—OHexadentates) insolubilizing/solubilizing groups attached. O ValenceStabilizer #19: Macrocyclic ligands containing a total of four, Four-,Five-, Six-, Seven-, Eight-, and Ten- five, six, seven, eight, or tensix-membered Membered Macrocyclics, Macrobicyclics, heterocyclic ringscontaining oxygen binding and Macropolycyclics (including sites. Caninclude other hydrocarbon or ring Catapinands, Cryptands, Cyclidenes,and systems bound to this macrocyclic ligand, but Sepulchrates) whereinall Binding Sites are they do not coordinate with the stabilized, highcomposed of Oxygen and are contained in valence metal ion. This ligandand/or attached, Component 6-Membered Heterocyclic uncoordinatinghydrocarbons/rings may or may Rings (O—O Bidentates, O—O Tridentates,not have halogen or polarizing or water- O—O Tetradentates, and O—OHexadentates) insolubilizing/solubilizing groups attached. N—S ValenceStabilizer #1: RC(═NH)SR′, where R and R′ represent H or Thioimidates,Dithioimidates, any organic functional group wherein thePolythioimidates, and Derivatives of number of carbon atoms ranges from0 to 40, Thioimidic Acid (N—S Bidentates and N—S optionally havinghalogen or polarizing or Tetradentates)water-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #2:RR′—N—C(═NH)—NR″—CS—NR″′R″″ for Thioguanylureas, Guanidinothioureas,thioguanylureas, and RR′—N—C(═NH)—NR″—NH— Bis(thioguanylureas),CS—NR″′R″″ for guanidinothioureas, where R, Bis(guanidinothioureas), R′,R″, R″′, and R″″ represent H, NH₂, or any Poly(thioguanylureas), andorganic functional group wherein the number of Poly(guanidinothioureas)(N—S Bidentates carbon atoms ranges from 0 to 40, optionally and N—STetradentates) having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #3:RR′—N—C(═NH)—NR″—CS—R″′ for N- Amidinothioamides, Guanidinothioamides,amidinothioamides, or RR′—N—C(═NH)— Bis(amidinothioamides),CR″R″′—CS—N—R″″R″″′ for 2- Bis(guanidinothioamides),amidinothioacetamides, and RR′—N—C(═NH)— Poly(amidinothioamides), andNR″—NH—CS—R″′ for guanidinothioamides, Poly(guanidinothioamides)(including both where R, R′, R″, R″′, R″″, and R″″′ representN-amidinothioamides and 2- H, NH₂, or any organic functional groupamidinothioacetamides) (N—S Bidentates wherein the number of carbonatoms ranges and N—S Tetradentates) from 0 to 40, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—SValence Stabilizer #4: R—C(═NH)—NR′—CS—R″, where R, R′, and R″,Imidoylthioamides, represent H or any organic functional groupBis(imidoylthioamides), and wherein the number of carbon atoms rangesPoly(imidoylthioamides) (N—S Bidentates from 0 to 40, optionally havinghalogen or and N—S Tetradentates) polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #5:RR′NCSNR″R″′, where R, R′, R″, and R″′ Thioureas, Bis(thioureas), andrepresent H, NH₂, or any organic functional Poly(thioureas), includingThiourylene group wherein the number of carbon atoms Complexes (N—SBidentates, N—S ranges from 0 to 40, optionally having halogenTridentates, and N—S Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #6: RCSNR′R″,where R, R′, and R″ represent H, Thiocarboxamides,Bis(thiocarboxamides), NH₂, or any organic functional group wherein andPoly(thiocarboxamides) (N—S the number of carbon atoms ranges from 0 toBidentates, N—S Tridentates, and N—S 40, optionally having halogen orpolarizing or Tetradentates) water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—SValence Stabilizer #7: RR′—N—S(═NH)—N—R″R″′, where R, R′, R″, andImidosulfurous Diamides and R″′ represent H or any organic functionalgroup Bis(imidosulfurous diamides) (N—S wherein the number of carbonatoms ranges Bidentates, N—S Tridentates, and N—S from 0 to 40,optionally having halogen or Tetradentates) polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #8:R—N═S═N—R′, where R and R′ represent H or Sulfurdiimines,Bis(sulfurdiimines), and any organic functional group wherein thePoly(sulfurdiimines) (N—S Bidentates, N—S number of carbon atoms rangesfrom 0 to 40, Tridentates, and N—S Tetradentates) optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—SValence Stabilizer #9: (NH═)PR(OR′)(SR″) for phosphonimidothioicPhosphonimidothioic Acid, acid and (NH═)PR(SR′)(SR″) forPhosphonimidodithioic Acid, phosphonimidodithioic acid, where R, R′, andBis(Phosphonimidothioic acid); R″ represent H or any organic functionalgroup Bis(Phosphonimidodithioic acid), and wherein the number of carbonatoms ranges derivatives thereof (N—S Bidentates, N—S from 0 to 40,optionally having halogen or Tetradentates) polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #10:(S═)PR(—NR′R″)(—NR″′R″″), where R, R′, R″, Phosphonothioic Diamides,R″′, and R″″ represent H or any organic Bis(phosphonothioic diamides),and functional group wherein the number of carbon Poly(phosphonothioicdiamides) (N—S atoms ranges from 0 to 40, optionally having Bidentatesand N—S Tetradentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #11:(S═)PR(—NR′R″)(—OR″′) or (O═)PR(—NR′R″)(—SR′′′) PhosphonamidothioicAcid, for phosphonamidothioic acid, (S═)PR(—NR′R″)Phosphonamidimidodithioic Acid, (—SR″′) for phosphonamidimidodithioicBis(phosphonamidothioic acid), acid, where R, R′, R″, and R″′ representH or Bis(phosphonamidimidodithioic acid), any organic functional groupwherein the poly(phosphonamidothioic acid), and number of carbon atomsranges from 0 to 40, poly(phosphonamidimidodithioic acid), andoptionally having halogen or polarizing or derivatives thereof (N—SBidentates and N—S water-insolubilizing/solubilizing groupsTetradentates) attached. Ligand can also contain nonbinding N, O, S, orP atoms. N—S Valence Stabilizer #12: R—C(═S)—CR′═CR″—NHR″′, where R, R′,R″, Beta-Aminothiones (N-Substituted 3- and R″′ represent H, or anyorganic functional amino-2-propenethioaldehydes), Bis(beta- groupwherein the number of carbon atoms aminothiones), and Poly(beta- rangesfrom 0 to 40, optionally having halogen aminothiones) (N—S Bidentatesand N—S or polarizing or water- Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #13:RR′—N—C(═S)—CR″═C(—NHR″′)R″″ for 3- 3-Aminothioacrylamides (3-Amino-2-aminothioacrylamides, and RR′—N—C(═S)— thiopropenamides), 3,3-CR″═C(—NHR″′)(—NR″″R″″′) for 3,3- Diaminothioacrylamides, Bis(3-diaminothioacrylamides, where R, R′, R″, R″′, aminothioacrylamides),Bis(3,3- R″″, R″″′ represent H, NH₂, or any organic diaminoacrylamides),Poly(3- functional group wherein the number of carbonaminothioacrylamides), and Poly(3,3- atoms ranges from 0 to 40,optionally having diaminothioacrylamides) (N—S Bidentates halogen orpolarizing or water- and N—S Tetradentates) insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.N—S Valence Stabilizer #14: R—O—C(═S)—CR′═C(—NHR″)R″′ or R—S—C(═S)—3-Aminothioacrylic Acids (3-Amino-2- CR′═C(—NHR″)R″′ for3-aminothioacrylic thiopropenoic acids), 3-Mercapto-3- acids, andR—O—C(═S)—CR′═C(—NHR″)(—S—R″′) aminothioacrylic acids, Bis(3- orR—S—C(═S)—CR′═C(—NHR″)(—S—R″′) for 3- aminothioacrylic acids),Bis(3-Hydroxy-3- mercapto-3-aminothioacrylic acids, where R,aminothioacrylic acids), Poly(3- R′, R″, and R″′ represent H, NH₂, orany aminothioacrylic acids), and Poly(3- organic functional groupwherein the number of Hydroxy-3-aminothioacrylic acids), and carbonatoms ranges from 0 to 40, optionally derivatives thereof (N—SBidentates and N—S having halogen or polarizing or water- Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #15:R—C(═S)—N═CHR′, where R′ represents an N-Thioacyl Benzylidenimines,Bis(N- aromatic derivative (i.e., —C₆H₅), and R thioacylbenzylidenimines), and Poly(N- represent H, NH₂, or any organicfunctional thioacyl benzylidenimines) (N—S Bidentates group wherein thenumber of carbon atoms and N—S Tetradentates) ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #16:R—C(═S)—C(═NOH)—R′, where R and R′ Thiocarbonyl oximes, Bis(thiocarbonylrepresent H, NH₂, or any organic functional oximes), andPoly(thiocarbonyl oximes) group wherein the number of carbon atoms (N—SBidentates, N—S Tridentates, and N—S ranges from 0 to 40, optionallyhaving halogen Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—S Valence Stabilizer #17:R—CH(—SH)—C(═NOH)—R′, where R, R′, and R″ Mercapto oximes, Bis(mercaptooximes), represent H, NH₂, or any organic functional and Poly(mercaptooximes) (including 2- group wherein the number of carbon atoms sulfurheterocyclic oximes) (N—S ranges from 0 to 40, optionally having halogenBidentates, N—S Tridentates, N—S or polarizing or water- Tetradentates,and N—S Hexadentates) insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. N—S ValenceStabilizer #18: o-(O₂N—)(HS—)Ar, where Ar represents an2-Nitrothiophenols (2-nitrobenzenethiols) aromatic group or heterocyclicwherein the (N—S Bidentates) number of carbon atoms ranges from 6 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #19:o-(NC—(CH₂)₀₋₁)(HS—)Ar, where Ar represents 2-Nitrilothiophenols (N—SBidentates) an aromatic group or heterocyclic wherein the number ofcarbon atoms ranges from 6 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer#20: R—C(═S)—NHNR′R″, where R, R′, and R″ Thiohydrazides,Bis(thiohydrazides), and represent H or any organic functional groupPoly(thiohydrazides) (N—S Bidentates and wherein the number of carbonatoms ranges N—S Tetradentates) from 0 to 40, optionally having halogenor polarizing or water-insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. N—S ValenceStabilizer #21: RR′—N—C(═S)—NHNR″R″′, where R, R′, and R″Thiosemicarbazides, represent H or any organic functional groupBis(thiosemicarbazides), and wherein the number of carbon atoms rangesPoly(thiosemicarbazides) (N—S Bidentates, from 0 to 40, optionallyhaving halogen or N—S Tetradentates, and N—S Hexadentates) polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—S Valence Stabilizer #22:Macrocyclic ligands containing five, seven, or Five-, Seven-, orNine-Membered nine binding sites composed of nitrogen and Macrocyclics,Macrobicyclics, and sulfur to valence stabilize the central metal ion.Macropolycyclics (including Catapinands, Can include other hydrocarbonor ring systems Cryptands, Cyclidenes, and Sepulchrates) bound to thismacrocyclic ligand, but they do wherein all Binding Sites are composedof not coordinate with the stabilized, high valence Nitrogen (usuallyamine or imine groups) or metal ion. This ligand and/or attached, Sulfur(usually thiols, mercaptans, or uncoordinating hydrocarbons/rings may ormay thiocarbonyls) and are not contained in not have halogen orpolarizing or water- Component Heterocyclic Rings (N—Sinsolubilizing/solubilizing groups attached. Tridentates, N—STetradentates, and N—S Hexadentates) N—S Valence Stabilizer #23:Macrocyclic ligands containing a total of five or Five-, orSeven-Membered Macrocyclics, seven heterocyclic rings containingnitrogen or Macrobicyclics, and Macropolycyclics sulfur binding sites.Can include other (including Catapinands, Cryptands, hydrocarbon/ringsystems bound to this Cyclidenes, and Sepulchrates) wherein allmacrocyclic ligand, but they do not coordinate Binding Sites arecomposed of Nitrogen or with the stabilized, high valence metal ion.This Sulfur and are contained in Component ligand and/or attached,uncoordinating Heterocyclic Rings (N—S Tridentates, N—Shydrocarbon/rings may or may not have halogen Tetradentates, or N—SHexadentates) or polarizing or water-insolubilizing groups attached. N—SValence Stabilizer #24: Macrocyclic ligands containing at least oneFive-, Seven-, or Nine-Membered heterocyclic ring. These heterocyclicrings Macrocyclics, Macrobicyclics, and provide nitrogen or sulfurbinding sites to Macropolycyclics (including Catapinands, valencestabilize the central metal ion. Other Cryptands, Cyclidenes, andSepulchrates) amine, imine, thiol, mercapto, or thiocarbonyl wherein allBinding Sites are composed of binding sites can also be included in theNitrogen or Sulfur and are contained in a macrocyclic ligand, so long asthe total number Combination of Heterocyclic Rings and of binding sitesis five, seven, or nine. Can Amine, Imine, Thiol, Mercapto, or includeother hydrocarbon/ring systems bound Thiocarbonyl Groups (N—STridentates, N—S to this macrocyclic ligand, but they do notTetradentates, or N—S Hexadentates) coordinate with the stabilized, highvalence metal ion. This ligand and/or attached, uncoordinatinghydrocarbon/rings may or may not have halogen or polarizing or water-insolubilizing groups attached. N—O Valence Stabilizer #1: RC(═NH)OR′,where R and R′ represent H or Imidates, Diimidates, Polyimidates, andany organic functional group wherein the Derivatives of Imidic Acid (N—OBidentates number of carbon atoms ranges from 0 to 40, and N—OTetradentates) optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #2:RR′NC(═NH)OR″, where R, R′, and R″ Pseudoureas, bis(pseudoureas), andrepresent H, NH₂, or any organic functional poly(pseudoureas) (N—OBidentates and N—O group wherein the number of carbon atomsTetradentates) ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer#3: RR′NC(═NH)CR″R″′(CO)OR″″, where R, R′, 2-Amidinoacetates,Bis(2-amidinoacetates), R″, R″′, and R″″ represent H, NH₂, or any andPoly(2-amidinoacetates) (N—O organic functional group wherein the numberof Bidentates and N—O Tetradentates) carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #4: RR′NCONR″R″′,where R, R′, R″, and R″′ Ureas, Bis(ureas), and Poly(ureas), representH, NH₂, or any organic functional including Urylene Complexes (N—O groupwherein the number of carbon atoms Bidentates, N—O Tridentates, and N—Oranges from 0 to 40, optionally having halogen Tetradentates) orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer#5: (NH═)PR(OR′)(OR″), where R, R′, and R″ Phosphonimidic Acid,Bis(phosphonimidic represent H, NH₂, or any organic functional acid),Poly(phosphonimidic acid), and group wherein the number of carbon atomsderivatives thereof (N—O Bidentates and N—O ranges from 0 to 40,optionally having halogen Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #6:(O═)PR(—NR′R″)(—OR″′) for phosphonamidic Phosphonamidic Acid, Phosphonicacid and (O═)PR(—NR′R″)(—NR″′R″″) for Diamide, Bis(Phosphonamidic Acid),phosphonic diamide, where R, R′, R″, R″′, and Bis(Phosphonic Diamide),R″″ represent H, NH₂, or any organic functional Poly(phosphonamidicacid), group wherein the number of carbon atoms poly(phosphonicdiamide), and derivatives ranges from 0 to 40, optionally having halogenthereof (N—O Bidentates and N—O or polarizing or water- Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #7:R—C(═O)—CR′═C(—NHR″)R″′, where R, R′, R″, Beta-Ketoamines (N-Substituted3-amino- and R″′ represent H, or any organic functional 2-propenals),Bis(beta-ketoamines), and group wherein the number of carbon atomsPoly(beta-ketoamines) (N—O Bidentates and ranges from 0 to 40,optionally having halogen N—O Tetradentates) or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #8:RR′—N—C(═O)—CR″═C(—NHR″′)R″″ for 3- 3-Aminoacrylamides (3-Amino-2-aminoacrylamides, and RR′—N—C(═O)—CR″═C propenamides),3,3-Diaminoacrylamides, (—NHR″′)(—NR″″R″″′) for 3,3-Bis(3-aminoacrylamides), Bis(3,3- diaminoacrylamides, where R, R′, R″,R″′, R″″, diaminoacrylamides), Poly(3- and R″″′ represent H, NH₂, or anyorganic aminoacrylamides), and Poly(3,3- functional group wherein thenumber of carbon diaminoacrylamides) (N—O Bidentates and atoms rangesfrom 0 to 40, optionally having N—O Tetradentates) halogen or polarizingor water- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #9:R—O—C(═O)—CR′═C(—NHR″)R″′ for 3- 3-Aminoacrylic Acids (3-Amino-2-aminoacrylic acids, and R—O—C(═O)—CR′═C propenoic acids), 3-Hydroxy-3-(—NHR″)(—O—R″′) for 3-hydroxy-3-aminoacrylic aminoacrylic acids,Bis(3-aminoacrylic acids, where R, R′, R″, and R″′ represent H, acids),Bis(3-Hydroxy-3-aminoacrylic NH₂, or any organic functional groupwherein acids), Poly(3-aminoacrylic acids), and the number of carbonatoms ranges from 0 to Poly(3-Hydroxy-3-aminoacrylic acids), and 40,optionally having halogen or polarizing or derivatives thereof (N—OBidentates and N—O water-insolubilizing/solubilizing groupsTetradentates) attached. Ligand can also contain nonbinding N, O, S, orP atoms. N—O Valence Stabilizer #10: R—C(═O)—N═CHR′, where R′ representsan N-Acyl Benzylidenimines, Bis(N-acyl aromatic derivative (i.e.,—C₆H₅), and R benzylidenimines), and Poly(N-acyl represent H, NH₂, orany organic functional benzylidenimines) (N—O Bidentates and N—O groupwherein the number of carbon atoms Tetradentates) ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #11:o-(O₂N—)(RR′N—)Ar, where Ar represents an 2-Nitroanilines (N—OBidentates) aromatic group or heterocyclic wherein the number of carbonatoms ranges from 6 to 40, and R and R′ represent H, NH₂, or alkyl oraryl hydrocarbon groups wherein the number of carbon atoms range from 0to 25, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #12:o-(NC—(CH₂)₀₋₁)(HO—)Ar, where Ar represents 2-Nitrilophenols (N—OBidentates). an aromatic group or heterocyclic wherein the Also includesacylcyanamides. number of carbon atoms ranges from 6 to 40, optionallyhaving halogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. N—OValence Stabilizer #13: HetN⁺—O⁻ for amine N-oxides, and R—N═N⁺(—O⁻)Amine N-Oxides and Diazine N-Oxides —R′ for diazine N-oxides (azoxycompounds), (Azoxy componds) (N—O Bidentates, N—O where Het represents anitrogen-containing Tridentates, and N—O Tetradentates) heterocyclicderivative wherein the number of carbon atoms ranges from 4 to 40, and Rand R′ represent separate or the same aromatic functionalities, both Hetand R,R′ optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. N—O Valence Stabilizer #14:R—C(═O)—NHNR′R″, where R, R′, and R″ Hydrazides, Bis(hydrazides), andrepresent H or any organic functional group Poly(hydrazides) (N—OBidentates and N—O wherein the number of carbon atoms rangesTetradentates) from 0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #15:RR′—N—C(═O)—NHNR″R″′, where R, R′, and R″ Semicarbazides,Bis(semicarbazides), and represent H or any organic functional groupPoly(semicarbazides) (N—O Bidentates, N—O wherein the number of carbonatoms ranges Tetradentates, and N—O Hexadentates) from 0 to 40,optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. N—O Valence Stabilizer #16:Macrocyclic ligands containing five, seven, or Five-, Seven-, orNine-Membered nine binding sites composed of nitrogen and Macrocyclics,Macrobicyclics, and oxygen to valence stabilize the central metalMacropolycyclics (including Catapinands, ion. Can include otherhydrocarbon or ring Cryptands, Cyclidenes, and Sepulchrates) systemsbound to this macrocyclic ligand, but wherein all Binding Sites arecomposed of they do not coordinate with the stabilized, high Nitrogen(usually amine or imine groups) or valence metal ion. This ligand and/orattached, Oxygen (usually hydroxy, carboxy, or uncoordinatinghydrocarbons/rings may or may carbonyl groups) and are not contained innot have halogen or polarizing or water- Component Heterocyclic Rings(N—O insolubilizing/solubilizing groups attached. Tridentates, N—OTetradentates, and N—O Hexadentates) N—O Valence Stabilizer #17:Macrocyclic ligands containing a total of five or Five-, orSeven-Membered Macrocyclics, seven heterocyclic rings containingnitrogen or Macrobicyclics, and Macropolycyclics oxygen binding sites.Can include other (including Catapinands, Cryptands, hydrocarbon/ringsystems bound to this Cyclidenes, and Sepulchrates) wherein allmacrocyclic ligand, but they do not coordinate Binding Sites arecomposed of Nitrogen or with the stabilized, high valence metal ion.This Oxygen and are contained in Component ligand and/or attached,uncoordinating Heterocyclic Rings (N—O Tridentates, N—Ohydrocarbon/rings may or may not have halogen Tetradentates, or N—OHexadentates) or polarizing or water-insolubilizing groups attached. N—OValence Stabilizer #18: Macrocyclic ligands containing at least oneFive-, Seven-, or Nine-Membered heterocyclic ring. These heterocyclicrings Macrocyclics, Macrobicyclics, and provide nitrogen or oxygenbinding sites to Macropolycyclics (including Catapinands, valencestabilize the central metal ion. Other Cryptands, Cyclidenes, andSepulchrates) amine, imine, hydroxy, carboxy, or carbonyl wherein allBinding Sites are composed of binding sites can also be included in theNitrogen or Oxygen and are contained in a macrocyclic ligand, so long asthe total number Combination of Heterocyclic Rings and of binding sitesis five, seven, or nine. Can Amine, Imine, Hydroxy, Carboxy, or includeother hydrocarbon/ring systems bound Carbonyl Groups (N—O Tridentates,N—O to this macrocyclic ligand, but they do not Tetradentates, or N—OHexadentates) coordinate with the stabilized, high valence metal ion.This ligand and/or attached, uncoordinating hydrocarbon/rings may or maynot have halogen or polarizing or water- insolubilizing groups attached.S—O Valence Stabilizer #1: RR′—N—C(═S)—NR″—C(═O)—NR″′R″″ for Thiobiurets(Thioimidodicarbonic thiobiurets, and RR′—N—C(═S)—NR″—NH—C(═O)—Diamides), Thioisobiurets, Thiobiureas, NR″′R″″ for thiobiureas, whereR, R′, R″, R″′, Thiotriurets, Thiotriureas, Bis(thiobiurets), and R″″represent H, NH₂, or any organic Bis(thioisobiurets), Bis(thiobiureas),functional group wherein the number of carbon Poly(thiobiurets),Poly(thioisobiurets), atoms ranges from 0 to 40, optionally havingPoly(thiobiureas) (S—O Bidentates, S—O halogen or polarizing or water-Tridentates, S—O Tetradentates), and 3- insolubilizing/solubilizinggroups attached. formamidino thiocarbamides Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #2:RR′—N—C(═S)—NR″—C(═O)—R″′ for acyl- and Acylthioureas, Aroylthioureas,aroylthioureas, and RR′—N—C(═O)—NR″—C(═S)—R″′ Thioacylureas,Thioaroylureas, for thioacyl- and thioaroylureas, where R,Bis(acylthioureas), Bis(aroylthioureas), R′, R″, and R″′ represent H,NH₂, or any Bis(thioacylureas), Bis(thioaroylureas), organic functionalgroup wherein the number of Poly(thioacylthioureas), carbon atoms rangesfrom 0 to 40, optionally Poly(thioaroylthioureas), having halogen orpolarizing or water- Poly(thioacylureas), andinsolubilizing/solubilizing groups attached. Poly(thioaroylureas) (S—OBidentates, S—O Ligand can also contain nonbinding N, O, S, orTridentates, S—O Tetradentates) P atoms. S—O Valence Stabilizer #3:RC(═S)—NR′—C(═O)—R″ for Thioimidodialdehydes, thioimidodialdehydes, andRC(═S)—NR′—NH— Thiohydrazidodialdehydes (thioacyl C(═O)—R″ forthiohydrazidodialdehydes hydrazides), Bis(thioimidodialdehydes),(thioacyl hydrazides), where R, R′, and R″Bis(thiohydrazidodialdehydes), represent H, NH₂, or any organicfunctional Poly(thioimidodialdehydes), and group wherein the number ofcarbon atoms Poly(thiohydrazidodialdehydes) (S—O ranges from 0 to 40,optionally having halogen Bidentates, S—O Tridentates, S—O or polarizingor water- Tetradentates) insolubilizing/solubilizing groups attached.Ligand can also contain nonbinding N, O, S, or P atoms. S—O ValenceStabilizer #4: R—O—C(═S)—NR′—C(═O)—O—R″ or R—S—C(═S)—Thioimidodicarbonic acids, NR′—C(═O)—S—R″ for thioimidodicarbonic acids,Thiohydrazidodicarbonic acids, and R—O—C(═S)—NR′—NH—C(═O)—O—R″ or R—S—Bis(thioimidodicarbonic acids), C(═S)—NR′—NH—C(═O)—S—R″ forBis(thiohydrazidodicarbonic acids), thiohydrazidodicarbonic acids, whereR, R′, and Poly(thioimidodicarbonic acids), R″ represent H, NH₂, or anyorganic functional Poly(thiohydrazidodicarbonic acids) and group whereinthe number of carbon atoms derivatives thereof (S—O Bidentates, S—Oranges from 0 to 40, optionally having halogen Tridentates, S—OTetradentates) or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #5: R—C(═S)—C(═O)—R′ where R and R′ represent H,1,2-Monothioketones (Monothiolenes, NH₂, or any organic functional groupwherein Monothio-alpha-ketonates), 1,2,3- the number of carbon atomsranges from 0 to Monothioketones, 1,2,3-Dithioketones, 40, optionallyhaving halogen or polarizing or Monothiotropolonates, ortho-water-insolubilizing/solubilizing groups Monothioquinones, Bis(1,2-attached. Ligand can also contain nonbinding N, Monothioketones), andPoly(1,2- O, S, or P atoms. Monothioketones) (S—O Bidentates, S—OTridentates, S—O Tetradentates) S—O Valence Stabilizer #6:RR′—N—C(═S)—S—S—C(═O)—N—R″R″′ for Trithioperoxydicarbonic Diamides,trithioperoxydicarbonic diamides, and RR′—N— DithioperoxydicarbonicDiamides, C(═O)—S—S—C(═O)—N—R″R″′ for Bis(trithioperoxydicarbonicdiamides), dithioperoxydicarbonic diamides, where R, R′,Bis(dithioperoxydicarbonic diamides), R″, R″′ represent H or any organicfunctional poly(trithioperoxydicarbonic diamides) and group wherein thenumber of carbon atoms poly(dithioperoxydicarbonic diamides) (S—O rangesfrom 0 to 40, optionally having halogen Bidentates, S—O Tridentates, S—Oor polarizing or water- Tetradentates) insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #7: R—O—C(═S)—S—C(═O)—O—R′, where R and R′Diithiodicarbonic Acids, represent H, NH₂ or any organic functionalBis(dithiodicarbonic acids), group wherein the number of carbon atomsPoly(dithiodicarbonic acids), and ranges from 0 to 40, optionally havinghalogen derivatives thereof (S—O Bidentates, S—O or polarizing or water-Tridentates, S—O Tetradentates) insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. S—OValence Stabilizer #8: R—O—C(═S)—S—S—C(═O)—O—R′, where R and R′Trithioperoxydicarbonic Acids, represent H, NH₂ or any organicfunctional Bis(trithioperoxydicarbonic acids), group wherein the numberof carbon atoms poly(trithioperoxydicarbonic acids), and ranges from 0to 40, optionally having halogen derivatives thereof (S—O Bidentates,S—O or polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #9:(RR′—N—)(R″R″′—N—)P(═S)—S—S—P(═O)(—N— Monothioperoxydiphosphoramide,R″″R″″′)(—N—R″″″R″″″′), where R, R′, R″, R″′,Bis(monothioperoxyphosphoramide), and R″″, R″″′, R″″″, and R″″″′represent H, NH₂ or Poly(monothioperoxydiphosphoramide) (S—O any organicfunctional group wherein the Bidentates, S—O Tridentates, S—O number ofcarbon atoms ranges from 0 to 40, Tetradentates) optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. S—OValence Stabilizer #10: (R—O—)(R′—O—)P(═S)—S—S—P(═O)(—O—R″)(—O—Monothioperoxydiphosphoric Acids, R″′); R″′);(R—O—)(R′—S—)P(═S)—S—S—P(═O)(—S—R″) Bis(monothioperoxyphosphoric Acids),(—O—R″′); or (R—S—)(R′—S—)P(═S)—S—S—P(═O)(—S—Poly(monothioperoxydiphosphoric Acids), R″)(—S—R″′), where R, R′, R″,R″′, R″″, R″″′, and derivatives thereof (S—O Bidentates, S—O R″″″, andR″″″′ represent H, NH₂ or any Tridentates, S—O Tetradentates) organicfunctional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #11:(R—O—)(R′—)P(═S)—NH—P(═O)(—R″)(—O—R″′); Monothioimidodiphosphonic Acids,(R—S—)(R′—)P(═S)—NH—P(═O)(—R″)(—O—R″′); MonothiohydrazidodiphosphonicAcids, or (R—S—)(R′—)P(═S)—NH—P(═O)(—R″)(—S—R″′)Bis(monothioimidodiphosphonic Acids), for monothioimidodiphosphonicacids, and —NH—NH— Bis(monothiohydrazidodiphosphonic derivatives formonothiohydrazidodiphosphonic acids, Acids),Poly(monothioimidodiphosphonic where R, R′, R″, and R″′ represent H, NH₂or any Acid), organic functional group wherein the number ofPoly(monothiohydrazidodiphosphonic carbon atoms ranges from 0 to 40,optionally Acids), and derivatives thereof (S—O having halogen orpolarizing or water- Bidentates, S—O Tridentates, S—Oinsolubilizing/solubilizing groups attached. Tetradentates) Ligand canalso contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #12:(RR′—N—)(R″—)P(═S)—NH—P(═O)(—R″′)(—N— Monothioimidodiphosphonamides,R″″R″″′) for monothioimidodiphosphonamides,Monothiohydrazidodiphosphonamides, and —NH—NH— derivatives forBis(monothioimidodiphosphonamides), monothiohydrazidodiphosphonamides,where R, Bis(monothiohydrazidodiphosphonamides) R′, R″, R″′, R″″, andR″″′, represent H, NH₂ or Poly(monothioimidodiphosphonamides), anyorganic functional group wherein the and number of carbon atoms rangesfrom 0 to 40, Poly(monothiohydrazidodiphosphonamides) optionally havinghalogen or polarizing or (S—O Bidentates, S—O Tridentates, S—Owater-insolubilizing/solubilizing groups Tetradentates) attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer#13: (RR′—N—)(R″—)P(═S)—S—P(═O)(R″′)(—N— Monothiodiphosphonamides,R″″R″″′), or (RR′—N—)(R″—)P(═S)—O—P(═O) Bis(monothioiphosphonamides),and (—R″′)(—N—R″″R″″′), where R, R′, R″, R″′, R″″,Poly(monothiodiphosphonamides) (S—O and R″″′ represent H, NH₂ or anyorganic Bidentates, S—O Tridentates, S—O functional group wherein thenumber of carbon Tetradentates) atoms ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #14: (R—O—)(R′—)P(═S)—O—P(═O)(—R″)(—O—R″′); (R—Monothiodiphosphonic Acids, O—)(R′—)P(═S)—S—P(═O)(—R″)(—O—R″′); (R—S—)Bis(monothioiphosphonic Acids), (R′—)P(═S)—O—P(═O)(—R″)(—S—R″′); or(R—S—) Poly(monothiodiphosphonic Acids), and(R′—)P(═S)—S—P(═O)(—R″)(—S—R″′), where R, derivatives thereof (S—OBidentates, S—O R′, R″, and R″′ represent H, NH₂ or any organicTridentates, S—O Tetradentates) functional group wherein the number ofcarbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer#15: RR′—N—)(R″—)P(═S)—S—S—P(═O)(—R″′)(—N—Monothioperoxydiphosphonamide, R″″R″″′), where R, R′, R″, R″′, R″″, andR″″′ Bis(monothioperoxyphosphonamide), and represent H, NH₂ or anyorganic functional Poly(monothioperoxydiphosphonamide) (S—O groupwherein the number of carbon atoms Bidentates, S—O Tridentates, S—Oranges from 0 to 40, optionally having halogen Tetradentates) orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer#16: (R—O—)(R′—)P(═S)—S—S—P(═O)(—R″)(—O—R″′); orMonothioperoxydiphosphonic Acids,(R—S—)(R′—)P(═S)—S—S—P(═O)(—R″)(—S—R″′), Bis(monothioperoxyphosphonicAcids), where R, R′, R″, and R″′ represent H, NH₂ orPoly(monothioperoxydiphosphonic Acids), any organic functional groupwherein the and derivatives thereof (S—O Bidentates, S—O number ofcarbon atoms ranges from 0 to 40, Tridentates, S—O Tetradentates)optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #17:(O═)P(—S—R)(—O—R′)(—O—R″) or (S═)P(—O—R)(—O— Monothiophosphoric AcidsR′)(—O—R″), where R, R′, and R″ represent H, (Phosphorothioic Acids),NH₂ or any organic functional group wherein Bis(monothiophosphoricacids), the number of carbon atoms ranges from 0 toPoly(monothiophosphoric acids), and 40, optionally having halogen orpolarizing or derivatives thereof (S—O Bidentates, S—Owater-insolubilizing/solubilizing groups Tridentates, S—O Tetradentates)attached. Ligand can also contain nonbinding N, O, S, or P atoms. S—OValence Stabilizer #18: (O═)P(—S—S—R)(—O—R′)(—O—R″), where R, R′,Phosphoro(dithioperoxoic) Acids, and R″ represent H, NH₂ or any organicBis[phosphoro(dithioperoxoic) acids], functional group wherein thenumber of carbon Poly[phosphoro(dithioperoxoic) acids], and atoms rangesfrom 0 to 40, optionally having derivatives thereof (S—O Bidentates, S—Ohalogen or polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #19:(O═)PR(—S—R′)(—O—R″) or (S═)PR(—O—R′)(—O—R″), Monothiophosphonic Acidswhere R, R′, and R″ represent H, NH₂ or (Phosphonothioic Acids), anyorganic functional group wherein the Bis(monothiophosphonic Acids),number of carbon atoms ranges from 0 to 40, Poly(monothiophosphonicAcids), and optionally having halogen or polarizing or derivativesthereof (S—O Bidentates, S—O water-insolubilizing/solubilizing groupsTridentates, S—O Tetradentates) attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #20:(O═)PR(—S—S—R′)(—O—R″), where R, R′, and R″ Phosphono(dithioperoxoic)Acids, represent H, NH₂ or any organic functionalBis[phosphono(dithioperoxoic) Acids], group wherein the number of carbonatoms Poly[phosphono(dithioperoxoic) Acids], ranges from 0 to 40,optionally having halogen and derivatives thereof (S—O Bidentates, S—Oor polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #21:R—CR′(—OH)—CH₂ —C(═S)—R″, where R, R′, and Beta-Hydroxythioketones,Beta- R″ represent H, NH₂ or any organic functionalHydroxythioaldehydes, Bis(beta- group wherein the number of carbon atomshydroxythioketones), Bis(beta- ranges from 0 to 40, optionally havinghalogen hydroxythioaldehydes), Poly(beta- or polarizing or water-hydroxythioketones), and Poly(beta- insolubilizing/solubilizing groupsattached. hydroxythioaldehydes) (S—O Bidentates, S—O Ligand can alsocontain nonbinding N, O, S, or Tridentates, S—O Tetradentates) P atoms.S—O Valence Stabilizer #22: R—CR′(—SH)—CH₂ —C(═O)—R″, where R, R′, andBeta-Mercaptoketones, Beta- R″ represent H, NH₂ or any organicfunctional Mercaptoaldehydes, Bis(beta- group wherein the number ofcarbon atoms mercaptoketones), Bis(beta- ranges from 0 to 40, optionallyhaving halogen mercaptoaldehydes), Poly(beta- or polarizing or water-mercaptoketones), and Poly(beta- insolubilizing/solubilizing groupsattached. mercaptoaldehydes) (S—O Bidentates, S—O Ligand can alsocontain nonbinding N, O, S, or Tridentates, S—O Tetradentates) P atoms.S—O Valence Stabilizer #23: RR′—N—CH(—OH)—NR″—C(═S)—NR″′R″″, whereN-(Aminomethylol)thioureas [N- R, R′, R″, R″′, and R″″ represent H, NH₂or any (Aminohydroxymethyl)thioureas], Bis[N- organic functional groupwherein the number of (aminomethylol)thioureas], and Poly[N- carbonatoms ranges from 0 to 40, optionally (aminomethylol)thioureas] (S—OBidentates, having halogen or polarizing or water- S—O Tridentates, S—OTetradentates) insolubilizing/solubilizing groups attached. Ligand canalso contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #24:RR′—N—CH(—SH)—NR″—C(═O)—NR″′R″″, where N-(Aminomethylthiol)ureas [N- R,R′, R″, R″′, and R″″ represent H, NH₂ or any(Aminomercaptomethyl)ureas], Bis[N- organic functional group wherein thenumber of (aminomethylthiol)ureas], and Poly[N- carbon atoms ranges from0 to 40, optionally (aminomethylthiol)ureas] (S—O Bidentates, havinghalogen or polarizing or water- S—O Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #25:RR′—N—C(═S)—C(═O)—N—R″R″′ where R, R′, Monothiooxamides, R″, and R″′represent H, NH₂ or any organic Bis(monothiooxamides), and functionalgroup wherein the number of carbon Poly(monothiooxamides) (S—OBidentates, atoms ranges from 0 to 40, optionally having S—OTridentates, S—O Tetradentates) halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #26:R—CR′(—SH)—CR″R″′—C(═O)(—O—R″″), where R, Beta-Mercapto CarboxylicAcids, Bis(Beta- R′, R″, R″′, and R″″ represent H, NH₂ or any MercaptoCarboxylic Acids), Poly(Beta- organic functional group wherein thenumber of Mercapto Carboxylic Acids), and carbon atoms ranges from 0 to40, optionally derivatives thereof (S—O Bidentates, S—O having halogenor polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #27:R—CR′(—SH)—CR″R″′—C(═O)(—S—R″″), where R, Beta-Mercapto ThiocarboxylicAcids, R′, R″, R″′, and R″″ represent H, NH₂ or any Bis(Beta-MercaptoThiocarboxylic Acids), organic functional group wherein the number ofPoly(Beta-Mercapto Thiocarboxylic Acids), carbon atoms ranges from 0 to40, optionally and derivatives thereof (S—O Bidentates, S—O havinghalogen or polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #28:R—CR′(—OH)—CR″R″′—C(═O)(—S—R″″), where R, Beta-Hydroxy ThiocarboxylicAcids, R′, R″, R″′, and R″″ represent H, NH₂ or any Bis(Beta-HydroxyThiocarboxylic Acids), organic functional group wherein the number ofPoly(Beta-Hydroxy Thiocarboxylic Acids), carbon atoms ranges from 0 to40, optionally and derivatives thereof (S—O Bidentates, S—O havinghalogen or polarizing or water- Tridentates, S—O Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. S—O Valence Stabilizer #29:R—CR′(—SH)—CR″R″′—C(═O)(—NH—R″″), where Beta-Mercapto Carboxamides,Bis(Beta- R, R′, R″, R″′, and R″″ represent H, NH₂ or any MercaptoCarboxamides), Poly(Beta- organic functional group wherein the number ofMercapto Carboxamides), and derivatives carbon atoms ranges from 0 to40, optionally thereof (S—O Bidentates, S—O Tridentates, having halogenor polarizing or water- S—O Tetradentates) insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #30: R—S—R′COOH for S-alkylthiocarboxylic and S-S-Alkylthiocarboxylic Acids, S- arylthiocarboxylic acids, and HOOCR—S—Arylthiocarboxylic Acids, and S,S- R′COOH for S,S-thiobiscarboxylicacids, where thiobiscarboxylic Acids (S—O Bidentates R and R′ representH or any organic functional and S—O Tridentates) group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer#31: R—S—S—R′COOH for S-alkyldisulfidocarboxylicS-Alkyldisulfidocarboxylic Acids, S- and S-aryldisulfidocarboxylicacids, and Aryldisulfidocarboxylic Acids, and S,S′- HOOCR—S—S—R′COOH forS,S′- Disulfidobiscarboxylic Acids (S—O disulfidobiscarboxylic acids,where R and R′ Bidentates and S—O Tridentates) represent H or anyorganic functional group wherein the number of carbon atoms ranges from0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #32:R—C(═O)(—S—R′) for monothiomonocarboxylic Monothiomonocarboxylic Acids,acids, and (R—S—)(O═)C—R′—C(═O)(—S—R″) or Dithiodicarboxylic Acids,(R—S—)(O═)C—R′—C(═O)(—O—R″) for Bis(monothiomonocarboxylic Acids),dithiodicarboxylic acids, where R, R′, and R″ Bis(dithiodicarboxylicacids), represent H, NH₂ or any organic functionalPoly(monothiomonocarboxylic acids), group wherein the number of carbonatoms Poly(dithiodicarboxylic acids), and ranges from 0 to 40,optionally having halogen derivatives thereof (S—O Bidentates and S—O orpolarizing or water- Tetradentates) insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. S—OValence Stabilizer #33: R—O—C(═S)—O—R′, where R, and R′ represent H,Monothiocarbonates and NH₂ or any organic functional group whereinBis(monothiocarbonates) (S—O Bidentates the number of carbon atomsranges from 0 to and S—O Tetradentates) 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer#34: RR′N—NR″—C(═O)(SH), where R and R′ Monothiocarbazates(Monothiocarbazides), represent H, NH₂ or any organic functionalBis(monothiocarbazates), and group wherein the number of carbon atomsPoly(monothiocarbazates) (S—O Bidentates, ranges from 0 to 40,optionally having halogen S—O Tridentates, and S—O Tetradentates; or orpolarizing or water- possibly N—S Bidentates, N—S Tridentates,insolubilizing/solubilizing groups attached. and N—S Tetradentates)Ligand can also contain nonbinding N, O, S, or P atoms. S—O ValenceStabilizer #35: R—CH(—SH)—CH(—OH)—R′ for alpha-mercapto MercaptoAlcohols and alcohols, R—CH(—SH)—Si(—OR′)_(x)—R″_(3-x) for alpha-Silylmercaptoalcohols, Bis(mercapto silylmercaptoalcohols,R—CH(—SH)—R′—CH(—OH)—R″ alcohols and silylmercaptoalcohols), and forbeta-mercapto alcohols, and Poly(mercapto alcohols andR—CH(—SH)—R′—Si(—OR″)_(x)—R″′_(3-x) for beta- silylmercaptoalcohols)(S—O Bidentates, S—O silylmercaptoalcohols, etc., where R, R′, R″,Tridentates, S—O Tetradentates) and R″′ represent H, NH₂ or any organicfunctional group wherein the number of carbon atoms ranges from 0 to 40,optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. x = 1-3. Ligand can alsocontain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer #36:RN═C(OH)(SH), where R represents H, NH₂ or Monothiocarbimates, anyorganic functional group wherein the Bis(monothiocarbimates), and numberof carbon atoms ranges from 0 to 40, Poly(monothiocarbimates) (S—OBidentates, optionally having halogen or polarizing or S—O Tridentates,and S—O Tetradentates) water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. S—OValence Stabilizer #37: R—O—C(—S—R″)—O—R′, where R, R′, and R″ Alkyl-and Aryl- Monothioborates and represent H, NH₂ or any organic functionalBis(monothioborates) (S—O Bidentates and group wherein the number ofcarbon atoms S—O Tetradentates) ranges from 0 to 40, optionally havinghalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. S—OValence Stabilizer #38: R—C(—S—R″)—O—R′, where R, R′, and R″ Alkyl- andAryl- Monothioboronates and represent H, NH₂ or any organic functionalBis(monothioboronates) (S—O Bidentates group wherein the number ofcarbon atoms and S—O Tetradentates) ranges from 0 to 40, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, O, S, or P atoms.S—O Valence Stabilizer #39: (O═)As(—S—R)(—O—R′)(—O—R″) or (S═)As(—O—Monothioarsonic Acids (Arsonothioic R)(—O—R′)(—O—R″), where R, R′, andR″ Acids), Bis(monothioarsonic acids), represent H, NH₂ or any organicfunctional Poly(monothioarsonic acids), and group wherein the number ofcarbon atoms derivatives thereof (S—O Bidentates, S—O ranges from 0 to40, optionally having halogen Tridentates, S—O Tetradentates) orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. S—O Valence Stabilizer#40: Heterocyclic ring(s) containing one or two Heterocyclic Ringscontaining One or Two sulfur atoms. In addition, ligand contains SulfurAtoms at least one additional additional oxygen-containing substituentsOxygen Atom Binding Site not in a Ring (usually hydroxy, carboxy, orcarbonyl groups) (S—O Bidentates, S—O Tridentates, S—O that constitute Obinding sites. Can include Tetradentates, or S—O Hexadentates) otherring systems bound to the heterocyclic ring or to the O-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, N, P, As or Se atoms.This 5-membered ring(s) and/or attached, uncoordinating rings and/or O-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. S—O ValenceStabilizer #41: Heterocyclic ring(s) containing one or two HeterocyclicRings containing One or Two oxygen atoms. In addition, ligand containsOxygen Atoms at least one additional additional sulfur-containingsubstituents Sulfur Atom Binding Site not in a Ring (S—O (usually thio,mercapto, or thiocarbonyl groups) Bidentates, S—O Tridentates, S—O thatconstitute S binding sites. Can include Tetradentates, or S—OHexadentates) other ring systems bound to the heterocyclic ring or tothe S-containing substituent, but they do not coordinate with thestabilized, high valence metal ion. Ring(s) can also contain O, N, P, Asor Se atoms. This 5-membered ring(s) and/or attached, uncoordinatingrings and/or S- containing substituent(s) may or may not have halogen orpolarizing or water- insolubilizing/solubilizing groups attached. S—OValence Stabilizer #42: Heterocyclic ring(s) containing one or twoHeterocyclic Rings containing One or Two sulfur atoms. In addition,ligand contains Sulfur Atoms at least one additional additionaloxygen-containing rings that Oxygen Atom Binding Site in a separateconstitute O binding sites. Can include other Ring (S—O Bidentates, S—OTridentates, S—O ring systems bound to the O-containing Tetradentates,or S—O Hexadentates) heterocyclic rings, but they do not coordinate withthe stabilized, high valence metal ion. Ring(s) can also contain O, N,P, As, or Se atoms. This 5-membered ring(s) and/or additionalO-containing ring(s) and/or attached, uncoordinating rings may or maynot have halogen or polarizing or water- insolubilizing/solubilizinggroups attached. S—O Valence Stabilizer #43: Macrocyclic ligandscontaining two to ten sulfur Two-, Three-, Four-, Five-, Six-, Seven-,or oxygen binding sites to valence stabilize the Eight-, Nine-, andTen-Membered central metal ion. Can include other Macrocyclics,Macrobicyclics, and hydrocarbon or ring systems bound to thisMacropolycyclics (including Catapinands, macrocyclic ligand, but they donot coordinate Cryptands, Cyclidenes, and Sepulchrates) with thestabilized, high valence metal ion. This wherein all Binding Sites arecomposed of ligand and/or attached, uncoordinating Sulfur (usuallythiol, mercapto, or hydrocarbons/rings may or may not have thiocarbonylgroups) or Oxygen (hydroxy, halogen or polarizing or water- carboxy, orcarbonyl groups) and are not insolubilizing/solubilizing groupsattached. contained in Component Heterocyclic Rings (S—O Bidentates, S—OTridentates, S—O Tetradentates, and S—O Hexadentates) S—O ValenceStabilizer #44: Macrocyclic ligands containing a total of four to Four-,Five-, Six-, Seven-, Eight-, Nine-, or ten five-membered heterocyclicrings containing Ten-Membered Macrocyclics, sulfur or oxygen bindingsites. Can include Macrobicyclics, and Macropolycyclics otherhydrocarbon/ring systems bound to this (including Catapinands,Cryptands, macrocyclic ligand, but they do not coordinate Cyclidenes,and Sepulchrates) wherein all with the stabilized, high valence metalion. This Binding Sites are composed of Sulfur or ligand and/orattached, uncoordinating Oxygen and are contained in Component 5-hydrocarbon/rings may or may not have halogen Membered HeterocyclicRings (S—O or polarizing or water-insolubilizing groups Tridentates, S—OTetradentates or S—O attached. Hexadentates) S—O Valence Stabilizer #45:Macrocyclic ligands containing at least one Four-, Five-, Six-, Seven-,Eight-, Nine-, or heterocyclic ring. These heterocyclic ringsTen-Membered Macrocyclics, provide sulfur or oxygen binding sites toMacrobicyclics, and Macropolycyclics valence stabilize the central metalion. Other (including Catapinands, Cryptands, thiol, mercapto,thiocarbonyl, hydroxy, carboxy, Cyclidenes, and Sepulchrates) whereinall or carbonyl binding sites can also be included in Binding Sites arecomposed of Sulfur or the macrocyclic ligand, so long as the totalOxygen and are contained in a Combination number of binding sites isfour to ten. Can of Heterocyclic Rings and Thiol, Mercapto, includeother hydrocarbon/ring systems bound Thiocarbonyl, Hydroxy, Carboxy, andto this macrocyclic ligand, but they do not Carbonyl Groups (S—OTridentates, S—O coordinate with the stabilized, high valenceTetradentates, or S—O Hexadentates) metal ion. This ligand and/orattached, uncoordinating hydrocarbon/rings may or may not have halogenor polarizing or water- insolubilizing groups attached. S—O ValenceStabilizer #46: Sulfoxides (R—SO—R′), where R and R′ Sulfoxides (S—OBidentates) represent H or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 35, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. S—OValence Stabilizer #47: Sulfones (R—SO₂—R′), where R and R′ representSulfones (S—O Bidentates) H or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 35, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. S—OValence Stabilizer #48: Sulfur dioxide ligands (—SO₂) bound directly toSulfur dioxide (SO₂) ligands (S—O the high valence metal ion.Bidentates) N—P Valence Stabilizer #1: [R(—NR′R″)(—PR″′R″″)],[R(—NR′R″)_(x)]₁₋₃P, Aminoaryl Phosphines and Iminoaryl[R(—NR′R″)_(x)]₁₋₃PX, or [R(—PR′R″)_(x)]₁₋₃N, where X = O Phosphines(N—P Bidentates, N—P or S and R, R′, R″, R″′, and R″″ representsTridentates, and N—P Tetradentates) H, NH₂ or any organic functionalgroup wherein the number of carbon atoms ranges from 0 to 35, optionallyhaving halogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, O, S, or Se atoms.N—P Valence Stabilizer #2: Five membered heterocyclic ring(s) containingHeterocyclic Rings containing One, Two, one, two, three, or fournitrogen atoms. In Three, or Four Nitrogen Atoms at least one addition,ligand contains additional phosphorus- additional Phosphorus AtomBinding Site containing substituents that constitute P binding not in aRing (N—P Bidentates, N—P sites. Can include other ring systems bound toTridentates, N—P Tetradentates, or N—P the heterocyclic ring or to theP-containing Hexadentates) substituent, but they do not coordinate withthe stabilized, high valence metal ion. Ring(s) can also contain O, S,or P atoms. This ring(s) and/or attached, uncoordinating rings and/or P-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. N—P ValenceStabilizer #3: Five membered heterocyclic ring(s) containingHeterocyclic Rings containing One, Two, one, two, or three phosphorusatoms. In or Three Phosphorus Atoms at least one addition, ligandcontains additional nitrogen- additional Nitrogen Atom Binding Site notcontaining substituents (usually amines, imines, in a Ring (N—PBidentates, N—P Tridentates, or hydrazides) that constitute N bindingsites. N—P Tetradentates, or N—P Hexadentates) Can include other ringsystems bound to the heterocyclic ring or to the N-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. Thisring(s) and/or attached, uncoordinating rings and/or N- containingsubstituent(s) may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. N—P Valence Stabilizer #4:Heterocyclic ring(s) containing one, two, three, Heterocyclic Ringscontaining One, Two, or four nitrogen atoms. In addition, ligand Three,or Four Nitrogen Atoms at least one contains additionalphosphorus-containing rings additional Phosphorus Atom Binding Site thatconstitute P binding sites. Can include in a Separate Ring (N—PBidentates, N—P other ring systems bound to the N- or P- Tridentates,N—P Tetradentates) containing heterocyclic rings, but they do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, S, or P atoms. This ring(s) and/or additional P- containingring(s) and/or attached, uncoordinating rings may or may not havehalogen or polarizing or water- insolubilizing/solubilizing groupsattached. N—P Valence Stabilizer #5: Macrocyclic ligands containing two,three, four, Two-, Three-, Four-, Five-, Six-, Seven-, five, six, seven,eight, nine, or ten binding sites Eight-, Nine-, and Ten-Memberedcomposed of nitrogen and phosphorus to Macrocyclics, Macrobicyclics, andvalence stabilize the central metal ion. Can Macropolycyclics (includingCatapinands, include other hydrocarbon or ring systems Cryptands,Cyclidenes, and Sepulchrates) bound to this macrocyclic ligand, but theydo wherein all Binding Sites are composed of not coordinate with thestabilized, high valence Nitrogen (usually amine or imine groups) ormetal ion. This ligand and/or attached, Phosphorus and are not containedin uncoordinating hydrocarbons/rings may or may Component HeterocyclicRings (N—P not have halogen or polarizing or water- Bidentates, N—PTridentates, N—P insolubilizing/solubilizing groups attached.Tetradentates, and N—P Hexadentates) N—P Valence Stabilizer #6:Macrocyclic ligands containing a total of four, Four-, Five-, Six-,Seven-, Eight-, Nine-, or five, six, seven, eight, nine, or tenheterocyclic Ten-Membered Macrocyclics, rings containing nitrogen orphosphorus binding Macrobicyclics, and Macropolycyclics sites. Caninclude other hydrocarbon/ring (including Catapinands, Cryptands,systems bound to this macrocyclic ligand, but Cyclidenes, andSepulchrates) wherein all they do not coordinate with the stabilized,high Binding Sites are composed of Nitrogen or valence metal ion. Thisligand and/or attached, Phosphorus and are contained in uncoordinatinghydrocarbon/rings may or may Component Heterocyclic Rings (N—P not havehalogen or polarizing or water- Bidentates, N—P Tridentates, N—Pinsolubilizing groups attached. Tetradentates, or N—P Hexadentates) N—PValence Stabilizer #7: Macrocyclic ligands containing at least oneFour-, Five-, Six-, Seven-, Eight-, Nine-, or heterocyclic ring. Theseheterocyclic rings Ten-Membered Macrocyclics, provide nitrogen orphosphorus binding sites to Macrobicyclics, and Macropolycyclics valencestabilize the central metal ion. Other (including Catapinands,Cryptands, amine, imine, or phosphine binding sites can Cyclidenes, andSepulchrates) wherein all also be included in the macrocyclic ligand, soBinding Sites are composed of Nitrogen or long as the total number ofbinding sites is four, Phosphorus and are contained in a five, six,seven, eight, nine, or ten. Can include Combination of HeterocyclicRings and other hydrocarbon/ring systems bound to this Amine, Imine, andPhosphine Groups (N—P macrocyclic ligand, but they do not coordinateBidentates, N—P Tridentates, N—P with the stabilized, high valence metalion. This Tetradentates, or N—P Hexadentates) ligand and/or attached,uncoordinating hydrocarbon/rings may or may not have halogen orpolarizing or water-insolubilizing groups attached. S—P ValenceStabilizer #1: [R(—SR′)_(x)]₁₋₃P, [R(—SR′)_(x)]₁₋₃PX,[R(—PR′R″)(—SR″′)], Thioaryl Phosphines (S—P Bidentates, S—P[R(—PR′R″)(—S—S—R″′)], [R(—PR′R″) Tridentates, and S—P Tetradentates)(—C(═S)R″′], [R(—PR′R″)_(x)]₂S, [R(—PR′R″)_(x)]₂₋₃ R″′(—SR″″)_(y),[R(—SR′)_(x)]₂₋₃R″(—PR″′R″″)_(y), [R(—PR′R″)_(x)]₂S₂, and[R(—PR′R″)_(x)]₂R″′(C(═S))_(y)R″″, where X = O or S, and R, R′, R″, R″′,and R″″ represent H, NH_(2,) or any organic functional group wherein thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water- insolubilizing/solubilizing groups attached, and x= 1-2 and y = 1-4. Ligand can also contain nonbinding N, O, S, or Patoms. S—P Valence Stabilizer #2: Heterocyclic ring(s) containing one ortwo Heterocyclic Rings containing One or Two sulfur atoms. In addition,ligand contains Sulfur Atoms at least one additional additionalphosphorus-containing substituents Phosphorus Atom Binding Site not in athat constitute P binding sites. Can include Ring (P—S Bidentates, P—STridentates, P—S other ring systems bound to the heterocyclicTetradentates, or P—S Hexadentates) ring or to the P-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. Thisring(s) and/or attached, uncoordinating rings and/or P-containingsubstituent(s) may or may not have halogen or polarizing orwater-insolubilizing/solubilizing groups attached. S—P ValenceStabilizer #3: Heterocyclic ring(s) containing one, two, or HeterocyclicRings containing One, Two, three phosphorus atoms. In addition, ligandor Three Phosphorus Atoms at least one contains additionalsulfur-containing additional Sulfur Atom Binding Site not insubstituents (usually thiol, mercapto, or a Ring (S—P Bidentates, S—PTridentates, S—P thiocarbonyl groups) that constitute S bindingTetradentates, or S—P Hexadentates) sites. Can include other ringsystems bound to the heterocyclic ring or to the S-containingsubstituent, but they do not coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, S, or P atoms. Thisring(s) and/or attached, uncoordinating rings and/or S- containingsubstituent(s) may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. S—P Valence Stabilizer #4:Heterocyclic ring(s) containing one or two Heterocyclic Rings containingOne or Two sulfur atoms. In addition, ligand contains Sulfur Atoms atleast one additional additional phosphorus-containing rings thatPhosphorus Atom Binding Site in a constitute P binding sites. Caninclude other Separate Ring (S—P Bidentates, S—P ring systems bound tothe S- or P-containing Tridentates, S—P Tetradentates) heterocyclicrings, but they do not coordinate with the stabilized, high valencemetal ion. Ring(s) can also contain O, S, or P atoms. This ring(s)and/or additional P-containing ring(s) and/or attached, uncoordinatingrings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. S—P Valence Stabilizer #5:Macrocyclic ligands containing two, three, four, Two-, Three-, Four-,Five-, Six-, Seven-, five, six, seven, eight, nine, or ten binding sitesEight-, Nine-, and Ten-Membered composed of sulfur and phosphorus tovalence Macrocyclics, Macrobicyclics, and stabilize the central metalion. Can include other Macropolycyclics (including Catapinands,hydrocarbon or ring systems bound to this Cryptands, Cyclidenes, andSepulchrates) macrocyclic ligand, but they do not coordinate wherein allBinding Sites are composed of with the stabilized, high valence metalion. This Sulfur (usually thiol, mercapto, or ligand and/or attached,uncoordinating thiocarbonyl groups) or Phosphorus and arehydrocarbons/rings may or may not have not contained in ComponentHeterocyclic halogen or polarizing or water- Rings (S—P Bidentates, S—PTridentates, S—P insolubilizing/solubilizing groups attached.Tetradentates, and S—P Hexadentates) S—P Valence Stabilizer #6:Macrocyclic ligands containing a total of four, Four-, Five-, Six-,Seven-, Eight-, Nine-, or five, six, seven, eight, nine, or tenheterocyclic Ten-Membered Macrocyclics, rings containing sulfur orphosphorus binding Macrobicyclics, and Macropolycyclics sites. Caninclude other hydrocarbon/ring (including Catapinands, Cryptands,systems bound to this macrocyclic ligand, but Cyclidenes, andSepulchrates) wherein all they do not coordinate with the stabilized,high Binding Sites are composed of Sulfur or valence metal ion. Thisligand and/or attached, Phosphorus and are contained in uncoordinatinghydrocarbon/rings may or may Component Heterocyclic Rings (S—P not havehalogen or polarizing or water- Bidentates, S—P Tridentates, S—Pinsolubilizing groups attached. Tetradentates, or S—P Hexadentates) S—PValence Stabilizer #7: Macrocyclic ligands containing at least oneFour-, Five-, Six-, Seven-, Eight-, Nine-, or heterocyclic ring. Theseheterocyclic rings Ten-Membered Macrocyclics, provide sulfur orphosphorus binding sites to Macrobicyclics, and Macropolycyclics valencestabilize the central metal ion. Other (including Catapinands,Cryptands, thiol, mercapto, or thiocarbonyl, or phosphine Cyclidenes,and Sepulchrates) wherein all binding sites can also be included in theBinding Sites are composed of Sulfur or macrocyclic ligand, so long asthe total number Phosphorus and are contained in a of binding sites isfour, five, six, seven, eight, Combination of Heterocyclic Rings andnine, or ten. Can include other Thiol, Mercapto, Thiocarbonyl orhydrocarbon/ring systems bound to this Phosphine Groups (S—P Bidentates,S—P macrocyclic ligand, but they do not coordinate Tridentates, S—PTetradentates, or S—P with the stabilized, high valence metal ion. ThisHexadentates) ligand and/or attached, uncoordinating hydrocarbon/ringsmay or may not have halogen or polarizing or water-insolubilizing groupsattached. P—O Valence Stabilizer #1: [R(—OR′)_(x)]₁₋₃P,[R(—OR′)_(x)]₁₋₃PX, [R(—PR′R″)(—OR″′)], Hydroxyaryl Phosphines (P—OBidentates, [R(—PR′R″)(—C(═O)R″′], [R(—PR′R″)_(x)]₂O, P—O Tridentates,and P—O Tetradentates) [R(—PR′R″)_(x)]₂₋₃R″′(—OR″″)_(y),[R(—OR′)_(x)]₂₋₃R″(—PR″′R″″)_(y), and [R(—PR′R″)_(x)]₂R″′(C(═O))_(y)R″″,where X = O or S, and R, R′, R″, R″′, and R″″ represent H, NH₂, or anyorganic functional group wherein the number of carbon atoms ranges from0 to 40, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached, and x = 1-2 and y =1-4. Ligand can also contain nonbinding N, O, S, or P atoms. P—O ValenceStabilizer #2: Heterocyclic ring(s) containing one or two HeterocyclicRings containing One or Two oxygen atoms. In addition, ligand containsOxygen Atoms at least one additional additional phosphorus-containingsubstituents Phosphorus Atom Binding Site not in a that constitute Pbinding sites. Can include Ring (P—O Bidentates, P—O Tridentates, P—Oother ring systems bound to the heterocyclic Tetradentates, or P—OHexadentates) ring or to the P-containing substituent, but they do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, S, or P atoms. This ring(s) and/or attached, uncoordinatingrings and/or P-containing substituent(s) may or may not have halogen orpolarizing or water-insolubilizing/solubilizing groups attached. P—OValence Stabilizer #3: Heterocyclic ring(s) containing one, two, orHeterocyclic Rings containing One, Two, three phosphorus atoms. Inaddition, ligand or Three Phosphorus Atoms at least one containsadditional oxygen-containing additional Oxygen Atom Binding Site notsubstituents (usually hydroxy, carboxy, or in a Ring (P—O Bidentates,P—O Tridentates, carbonyl groups) that constitute O binding sites. P—OTetradentates, or P—O Hexadentates) Can include other ring systems boundto the heterocyclic ring or to the O-containing substituent, but they donot coordinate with the stabilized, high valence metal ion. Ring(s) canalso contain O, S, or P atoms. This ring(s) and/or attached,uncoordinating rings and/or O- containing substituent(s) may or may nothave halogen or polarizing or water- insolubilizing/solubilizing groupsattached. P—O Valence Stabilizer #4: Heterocyclic ring(s) containing oneor two Heterocyclic Rings containing One or Two oxygen atoms. Inaddition, ligand contains Oxygen Atoms at least one additionaladditional phosphorus-containing rings that Phosphorus Atom Binding Sitein a constitute P binding sites. Can include other Separate Ring (P—OBidentates, P—O ring systems bound to the O- or P-containingTridentates, P—O Tetradentates) heterocyclic rings, but they do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, S, or P atoms. This ring(s) and/or additional P-containingring(s) and/or attached, uncoordinating rings may or may not havehalogen or polarizing or water- insolubilizing/solubilizing groupsattached. P—O Valence Stabilizer #5: Macrocyclic ligands containing two,three, four, Two-, Three-, Four-, Five-, Six-, Seven-, five, six, seven,eight, nine, or ten binding sites Eight-, Nine-, and Ten-Memberedcomposed of oxygen and phosphorus to valence Macrocyclics,Macrobicyclics, and stabilize the central metal ion. Can include otherMacropolycyclics (including Catapinands, hydrocarbon or ring systemsbound to this Cryptands, Cyclidenes, and Sepulchrates) macrocyclicligand, but they do not coordinate wherein all Binding Sites arecomposed of with the stabilized, high valence metal ion. This Oxygen(usually hydroxy, carboxy, or ligand and/or attached, uncoordinatingcarbonyl groups) or Phosphorus and are not hydrocarbons/rings may or maynot have contained in Component Heterocyclic halogen or polarizing orwater- Rings (P—O Bidentates, P—O Tridentates, P—Oinsolubilizing/solubilizing groups attached. Tetradentates, and P—OHexadentates) P—O Valence Stabilizer #6: Macrocyclic ligands containinga total of four, Four-, Five-, Six-, Seven-, Eight-, Nine-, or five,six, seven, eight, nine, or ten heterocyclic Ten-Membered Macrocyclics,rings containing oxygen or phosphorus binding Macrobicyclics, andMacropolycyclics sites. Can include other hydrocarbon/ring (includingCatapinands, Cryptands, systems bound to this macrocyclic ligand, butCyclidenes, and Sepulchrates) wherein all they do not coordinate withthe stabilized, high Binding Sites are composed of Oxygen or valencemetal ion. This ligand and/or attached, Phosphorus and are contained inuncoordinating hydrocarbon/rings may or may Component Heterocyclic Rings(P—O not have halogen or polarizing or water- Bidentates, P—OTridentates, P—O insolubilizing groups attached. Tetradentates, or P—OHexadentates) P—O Valence Stabilizer #7: Macrocyclic ligands containingat least one Four-, Five-, Six-, Seven-, Eight-, Nine-, or heterocyclicring. These heterocyclic rings Ten-Membered Macrocyclics, provide oxygenor phosphorus binding sites to Macrobicyclics, and Macropolycyclicsvalence stabilize the central metal ion. Other (including Catapinands,Cryptands, hydroxy, carboxy, carbonyl, or phosphine Cyclidenes, andSepulchrates) wherein all binding sites can also be included in theBinding Sites are composed of Oxygen or macrocyclic ligand, so long asthe total number Phosphorus and are contained in a of binding sites isfour, five, six, seven, eight, Combination of Heterocyclic Rings andnine, or ten. Can include other Hydroxy, Carboxy, Carbonyl or Phosphinehydrocarbon/ring systems bound to this Groups (P—O Bidentates, P—OTridentates, macrocyclic ligand, but they do not coordinate P—OTetradentates, or P—O Hexadentates) with the stabilized, high valencemetal ion. This ligand and/or attached, uncoordinating hydrocarbon/ringsmay or may not have halogen or polarizing or water-insolubilizing groupsattached. As Valence Stabilizer #1: AsH₃, AsH₂R, AsHR₂, where Rrepresents H or Monoarsines (As Monodentates) wherein at any organicfunctional group wherein the least one Arsenic Atom is a Binding Sitenumber of carbon atoms ranges from 0 to 25, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, P, As, O, S, or Se atoms. As ValenceStabilizer #2: R′—As—R—As—R″, where R, R′, and R″ represent Diarsines(an As—As Bidentate) wherein at H or any organic functional groupwherein the least one Arsenic Atom is a Binding Site number of carbonatoms ranges from 0 to 25, optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, As, O, S, or Se atoms. As Valence Stabilizer#3: R—As—R′—As—R″—As—R″′, where R, R′, R″, and Triarsines (either As—AsBidentates or As— R″′ represent H or any organic functional group AsTridentates) wherein at least one wherein the number of carbon atomsranges Arsenic Atom is a Binding Site from 0 to 25, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, As, O, S, or Seatoms. As Valence Stabilizer #4: R—As—R′—As—R″—As—R″′—As—R″″, where R,R′, Tetraarsines (As—As Bidentates, As—As R″, R″′, and R″″ represent Hor any organic Tridentates, or As—As Tetradentates) functional groupwherein the number of carbon wherein at least one Arsenic Atom is aatoms ranges from 0 to 25, optionally having Binding Site halogen orpolarizing or water- insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, P, As, O, S, or Se atoms. As ValenceStabilizer #5: R—As—R′—As—R″—As—R″′—As—R″″—As—R″″′, Pentaarsines (As—AsBidentates, As—As where R, R′, R″, R″′, R″″, and R″″′ represent HTridentates, or As—As Tetradentates) or any organic functional groupwherein the wherein at least one Arsenic Atom is a number of carbonatoms ranges from 0 to 25, Binding Site optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, P, As, O, S, or Se atoms. As ValenceStabilizer #6: R—As—R′—As—R″—As—R″′—As—R″″—As—R″″′—As— Hexaarsines(As—As Bidentates, As—As R″″″, where R, R′, R″, R″′, R″″, R″″′, andTridentates, As—As Tetradentates, or As—As R″″″ represent H or anyorganic functional Hexadentates) wherein at least one Arsenic groupwherein the number of carbon atoms Atom is a Binding Site ranges from 0to 25, optionally having halogen or polarizing or water-insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, P, As, O, S, or Se atoms. As Valence Stabilizer #7: Fivemembered heterocyclic ring containing just Five-Membered HeterocyclicRings one arsenic binding site. Can include other ring containing OneArsenic Atom wherein the systems bound to this heterocyclic ring, butthey Arsenic Atom is the Binding Site (As do not coordinate with thestabilized, high Monodentates) valence metal ion. Ring can also containO, S, N, P, or Se atoms. This 5-membered ring and/or attached,uncoordinating rings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. As Valence Stabilizer #8:Six membered heterocyclic ring containing just Six-Membered HeterocyclicRings one arsenic binding site. Can include other ring containing OneArsenic Atom wherein the systems bound to this heterocyclic ring, butthey Arsenic Atom is the Binding Site (As do not coordinate with thestabilized, high Monodentates) valence metal ion. Ring can also containO, S, N, P, or Se atoms. This 6-membered ring and/or attached,uncoordinating rings may or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. As Valence Stabilizer #9:Five membered heterocyclic ring(s) containing Five-Membered HeterocyclicRings one arsenic atom. In addition, ligand contains containing OneArsenic Atom and having at additional arsenic-containing substituentsleast one additional Arsenic Atom Binding (usually arsines) thatconstitute As binding sites. Site not in a Ring (As Monodentates, As—AsCan include other ring systems bound to the Bidentates, As—AsTridentates, As—As heterocyclic ring or to the As-containingTetradentates, or As—As Hexadentates) substituent, but they do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, N, S, P or Se atoms. This 5- membered ring(s) and/orattached, uncoordinating rings and/or As-containing substituent(s) mayor may not have halogen or polarizing orwater-insolubilizing/solubilizing groups attached. As Valence Stabilizer#10: Six membered heterocyclic ring(s) containing Six-MemberedHeterocyclic Rings one arsenic atom. In addition, ligand containscontaining One Arsenic Atom and having at additional arsenic-containingsubstituents least one additional Arsenic Atom Binding (usually arsines)that constitute As binding sites. Site not in a Ring (As Monodentates,As—As Can include other ring systems bound to the Bidentates, As—AsTridentates, As—As heterocyclic ring or to the As-containingTetradentates, or As—As Hexadentates) substituent, but they do notcoordinate with the stabilized, high valence metal ion. Ring(s) can alsocontain O, N, S, P or Se atoms. This 6- membered ring(s) and/orattached, uncoordinating rings and/or As-containing substituent(s) mayor may not have halogen or polarizing orwater-insolubilizing/solubilizing groups attached. As Valence Stabilizer#11: Five membered heterocyclic ring(s) containing Five-MemberedHeterocyclic Rings one arsenic atom. In addition, ligand containscontaining One Arsenic Atom and having at additional arsenic-containingrings that least one additional Arsenic Atom Binding constitute Asbinding sites. Can include other Site in a separate Ring (AsMonodentates, ring systems bound to the As-containing As—As Bidentates,As—As Tridentates, heterocyclic rings, but they do not coordinate As—AsTetradentates, or As—As Hexadentates) with the stabilized, high valencemetal ion. Ring(s) can also contain O, N, S, P, or Se atoms. This5-membered ring(s) and/or additional As-containing ring(s) and/orattached, uncoordinating rings may or may not have halogen or polarizingor water- insolubilizing/solubilizing groups attached. As ValenceStabilizer #12: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one arsenic atom. In addition, ligandcontains containing One Arsenic Atom and having at additionalarsenic-containing rings that least one additional Arsenic Atom Bindingconstitute As binding sites. Can include other Site in a separate Ring(As Monodentates, ring systems bound to the As-containing As—AsBidentates, As—As Tridentates, heterocyclic rings, but they do notcoordinate As—AS Tetradentates, or As—As Hexadentates) with thestabilized, high valence metal ion. Ring(s) can also contain O, N, S, P,or Se atoms. This 6-membered ring(s) and/or additional As-containingring(s) and/or attached, uncoordinating rings may or may not havehalogen or polarizing or water- insolubilizing/solubilizing groupsattached. As Valence Stabilizer #13: Macrocyclic ligands containing two,three, four, Two-, Three-, Four-, and Six-Membered or six arsenicbinding sites to valence stabilize Macrocyclics, Macrobicyclics, and thecentral metal ion. Can include other Macropolycyclics (includingCatapinands, hydrocarbon or ring systems bound to this Cryptands,Cyclidenes, and Sepulchrates) macrocyclic ligand, but they do notcoordinate wherein all Binding Sites are composed of with thestabilized, high valence metal ion. This Arsenic and are not containedin ligand and/or attached, uncoordinating Component Heterocyclic Rings(As—As hydrocarbons/rings may or may not have Bidentates, As—AsTridentates, As—As halogen or polarizing or water- Tetradentates, andAs—As Hexadentates) insolubilizing/solubilizing groups attached. AsValence Stabilizer #14: Macrocyclic ligands containing a total of fouror Four-, or Six-Membered Macrocyclics, six five-membered heterocyclicrings containing Macrobicyclics, and Macropolycyclics arsenic bindingsites. Can include other (including Catapinands, Cryptands,hydrocarbon/ring systems bound to this Cyclidenes, and Sepulchrates)wherein all macrocyclic ligand, but they do not coordinate Binding Sitesare composed of Arsenic and with the stabilized, high valence metal ion.This are contained in Component 5-Membered ligand and/or attached,uncoordinating Heterocyclic Rings (As—As Tridentates, hydrocarbon/ringsmay or may not have halogen As—As Tetradentates, or As—As Hexadentates)or polarizing or water-insolubilizing groups attached. As ValenceStabilizer #15: Macrocyclic ligands containing at least one 5- Four-, orSix-Membered Macrocyclics, membered heterocyclic ring. TheseMacrobicyclics, and Macropolycyclics heterocyclic rings provide arsenicbinding sites (including Catapinands, Cryptands, to valence stabilizethe central metal ion. Other Cyclidenes, and Sepulchrates) wherein allarsine binding sites can also be included in the Binding Sites arecomposed of Arsenic and macrocyclic ligand, so long as the total numberare contained in a Combination of 5- of binding sites is four or eight.Can include Membered Heterocyclic Rings and Arsine otherhydrocarbon/ring systems bound to this Groups (As—As Tridentates, As—Asmacrocyclic ligand, but they do not coordinate Tetradentates, or As—AsHexadentates) with the stabilized, high valence metal ion. This ligandand/or attached, uncoordinating hydrocarbon/rings may or may not havehalogen or polarizing or water-insolubilizing groups attached. AsValence Stabilizer #16: Macrocyclic ligands containing a total of fouror Four-, or Six-Membered Macrocyclics, six six-membered heterocyclicrings containing Macrobicyclics, and Macropolycyclics arsenic bindingsites. Can include other (including Catapinands, Cryptands,hydrocarbon/ring systems bound to this Cyclidenes, and Sepulchrates)wherein all macrocyclic ligand, but they do not coordinate Binding Sitesare composed of Arsenic and with the stabilized, high valence metal ion.This are contained in Component 6-Membered ligand and/or attached,uncoordinating Heterocyclic Rings (As—As Tridentates, hydrocarbon/ringsmay or may not have halogen As—As Tetradentates, or As—As Hexadentates)or polarizing or water-insolubilizing groups attached. As ValenceStabilizer #17: Macrocyclic ligands containing at least one 6- Four-, orSix-Membered Macrocyclics, membered heterocyclic ring. TheseMacrobicyclics, and Macropolycyclics heterocyclic rings provide arsenicbinding sites (including Catapinands, Cryptands, to valence stabilizethe central metal ion. Other Cyclidenes, and Sepulchrates) wherein allarsine binding sites can also be included in the Binding Sites arecomposed of Arsenic and macrocyclic ligand, so long as the total numberare contained in a Combination of 6- of binding sites is four or six.Can include other Membered Heterocyclic Rings and Arsinehydrocarbon/ring systems bound to this Groups (As—As Tridentates, As—Asmacrocyclic ligand, but they do not coordinate Tetradentates, or As—AsHexadentates) with the stabilized, high valence metal ion. This ligandand/or attached, uncoordinating hydrocarbon/rings may or may not havehalogen or polarizing or water-insolubilizing groups attached. SeValence Stabilizer #1: SeH₂, SeHR, SeR₂, where R represents H or anyMonoselenoethers (Se Monodentates) organic functional group wherein thenumber of wherein at least one Selenium Atom is a carbon atoms rangesfrom 0 to 25, optionally Binding Site having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, O, S, or Se atoms. Se Valence Stabilizer #2:R—Se—R′—Se—R″, where R, R′, and R″ represents Diselenoethers (Se—SeBidentates) wherein H or any organic functional group wherein the atleast one Selenium Atom is a Binding number of carbon atoms ranges from0 to 25, Site optionally having halogen or polarizing orwater-insolubilizing/solubilizing groups attached. Ligand can alsocontain nonbinding N, P, O, S, or Se atoms. Se Valence Stabilizer #3:R—Se—R′—Se—R″—Se—R″′, where R, R′, R″, and Triselenoethers (Se—SeBidentates or Se—Se R″′ represents H or any organic functionalTridentates) wherein at least one Selenium group wherein the number ofcarbon atoms Atom is a Binding Site ranges from 0 to 25, optionallyhaving halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Ligand can also contain nonbinding N, P, O, S, or Seatoms. Se Valence Stabilizer #4: R—Se—R′—Se—R″—Se—R″′—Se—R″″, where R,R′, Tetraselenoethers (Se—Se Bidentates, Se—Se R″, R″′, and R″″represents H or any organic Tridentates, or Se—Se Tetradentates)functional group wherein the number of carbon wherein at least oneSelenium Atom is a atoms ranges from 0 to 25, optionally having BindingSite halogen or polarizing or water- insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, P, O, S, or Se atoms. SeValence Stabilizer #5: Five membered heterocyclic ring containing oneFive-Membered Heterocyclic Rings or two selenium atoms, both of whichmay containing One or Two Selenium Atoms function as binding sites. Caninclude other wherein at least one Selenium Atom is a ring systems boundto this heterocyclic ring, but Binding Site (Se Monodentates or Se—Sethey do not coordinate with the stabilized, high Bidentates) valencemetal ion. Ring can also contain O, N, P, As, or S atoms. This5-membered ring and/or attached, uncoordinating rings may or may nothave halogen or polarizing or water- insolubilizing/solubilizing groupsattached. Se Valence Stabilizer #6: Six membered heterocyclic ringcontaining one Six-Membered Heterocyclic Rings or two selenium atoms,both of which may containing One or Two Selenium Atoms function asbinding sites. Can include other wherein at least one Selenium Atom is aring systems bound to this heterocyclic ring, but Binding Site (SeMonodentates or Se—Se they do not coordinate with the stabilized, highBidentates) valence metal ion. Ring can also contain O, N, P, As, or Satoms. This 5-membered ring and/or attached, uncoordinating rings may ormay not have halogen or polarizing or water- insolubilizing/solubilizinggroups attached. Se Valence Stabilizer #7: Five membered heterocyclicring(s) containing Five-Membered Heterocyclic Rings one selenium atom.In addition, ligand contains containing One Selenium Atom and havingadditional selenium-containing substituents at least one additionalSelenium Atom (usually selenols or selenoethers) that constitute BindingSite not in a Ring (Se Se binding sites. Can include other ringMonodentates, Se—Se Bidentates, Se—Se systems bound to the heterocyclicring or to the Tridentates, Se—Se Tetradentates, or Se—Se Se-containingsubstituent, but they do not Hexadentates) coordinate with thestabilized, high valence metal ion. Ring(s) can also contain O, N, P, Asor S atoms. This 5-membered ring(s) and/or attached, uncoordinatingrings and/or Se- containing substituent(s) may or may not have halogenor polarizing or water- insolubilizing/solubilizing groups attached. SeValence Stabilizer #8: Six membered heterocyclic ring(s) containingSix-Membered Heterocyclic Rings one selenium atom. In addition, ligandcontains containing One Selenium Atom and having additionalselenium-containing substituents at least one additional Selenium Atom(usually selenols or selenoethers) that constitute Binding Site not in aRing (Se Se binding sites. Can include other ring Monodentates, Se—SeBidentates, Se—Se systems bound to the heterocyclic ring or to theTridentates, Se—Se Tetradentates, or Se—Se Se-containing substituent,but they do not Hexadentates) coordinate with the stabilized, highvalence metal ion. Ring(s) can also contain O, N, P, As or S atoms. This6-membered ring(s) and/or attached, uncoordinating rings and/or Se-containing substituent(s) may or may not have halogen or polarizing orwater- insolubilizing/solubilizing groups attached. Se ValenceStabilizer #9: Five membered heterocyclic ring(s) containingFive-Membered Heterocyclic Rings one selenium atom. In addition, ligandcontains containing One Selenium Atom and having additionalselenium-containing rings that at least one additional Selenium Atomconstitute Se binding sites. Can include other Binding Site in aseparate Ring (Se ring systems bound to the Se-containing Monodentates,Se—Se Bidentates, Se—Se heterocyclic rings, but they do not coordinateTridentates, Se—Se Tetradentates, or Se—Se with the stabilized, highvalence metal ion. Hexadentates) Ring(s) can also contain O, N, P, As,or S atoms. This 5-membered ring(s) and/or additional Se-containingring(s) and/or attached, uncoordinating rings may or may not havehalogen or polarizing or water- insolubilizing/solubilizing groupsattached. Se Valence Stabilizer #10: Six membered heterocyclic ring(s)containing Six-Membered Heterocyclic Rings one selenium atom. Inaddition, ligand contains containing One Selenium Atom and havingadditional selenium-containing rings that at least one additionalSelenium Atom constitute Se binding sites. Can include other BindingSite in a separate Ring (Se ring systems bound to the Se-containingMonodentates, Se—Se Bidentates, Se—Se heterocyclic rings, but they donot coordinate Tridentates, Se—Se Tetradentates, or Se—Se with thestabilized, high valence metal ion. Hexadentates) Ring(s) can alsocontain O, N, P, As, or S atoms. This 6-membered ring(s) and/oradditional Se-containing ring(s) and/or attached, uncoordinating ringsmay or may not have halogen or polarizing or water-insolubilizing/solubilizing groups attached. Se Valence Stabilizer #11:Macrocyclic ligands containing two, three, four, Two-, Three-, Four-, orSix-Membered or six selenium binding sites to valence stabilizeMacrocyclics, Macrobicyclics, and the central metal ion. Can includeother Macropolycyclics (including Catapinands, hydrocarbon or ringsystems bound to this Cryptands, Cyclidenes, and Sepulchrates)macrocyclic ligand, but they do not coordinate wherein all Binding Sitesare composed of with the stabilized, high valence metal ion. ThisSelenium (usually selenol or selenoether ligand and/or attached,uncoordinating groups) and are not contained in hydrocarbons/rings mayor may not have Component Heterocyclic Rings (Se—Se halogen orpolarizing or water- Bidentates, Se—Se Tridentates, Se—Seinsolubilizing/solubilizing groups attached. Tetradentates, or Se—SeHexadentates) Se Valence Stabilizer #12: Macrocyclic ligands containinga total of four or Four-, or Six-Membered Macrocyclics, sixfive-membered heterocyclic rings containing Macrobicyclics, andMacropolycyclics selenium binding sites. Can include other (includingCatapinands, Cryptands, hydrocarbon/ring systems bound to thisCyclidenes, and Sepulchrates) wherein all macrocyclic ligand, but theydo not coordinate Binding Sites are composed of Selenium with thestabilized, high valence metal ion. This and are contained in Component5- ligand and/or attached, uncoordinating Membered Heterocyclic Rings(Se—Se hydrocarbon/rings may or may not have halogen Tridentates, Se—SeTetradentates or Se—Se or polarizing or water-insolubilizing groupsHexadentates) attached. Se Valence Stabilizer #13: Macrocyclic ligandscontaining at least one 5- Four-, or Six-Membered Macrocyclics, memberedheterocyclic ring. These Macrobicyclics, and Macropolycyclicsheterocyclic rings provide selenium binding (including Catapinands,Cryptands, sites to valence stabilize the central metal ion. Cyclidenes,and Sepulchrates) wherein all Other selenol or selenoether binding sitescan Binding Sites are composed of Selenium also be included in themacrocyclic ligand, so and are contained in a Combination of 5- long asthe total number of binding sites is four Membered Heterocyclic Ringsand Selenol or six. Can include other hydrocarbon/ring or SelenoetherGroups (Se—Se Tridentates, systems bound to this macrocyclic ligand, butSe—Se Tetradentates, or Se—Se they do not coordinate with thestabilized, high Hexadentates) valence metal ion. This ligand and/orattached, uncoordinating hydrocarbon/rings may or may not have halogenor polarizing or water- insolubilizing groups attached. Se ValenceStabilizer #14: Macrocyclic ligands containing a total of four or Four-,or Six-Membered Macrocyclics, six six-membered heterocyclic ringscontaining Macrobicyclics, and Macropolycyclics selenium binding sites.Can include other (including Catapinands, Cryptands, hydrocarbon/ringsystems bound to this Cyclidenes, and Sepulchrates) wherein allmacrocyclic ligand, but they do not coordinate Binding Sites arecomposed of Selenium with the stabilized, high valence metal ion. Thisand are contained in Component 6- ligand and/or attached, uncoordinatingMembered Heterocyclic Rings (Se—Se hydrocarbon/rings may or may not havehalogen Tridentates, Se—Se Tetradentates, or Se—Se or polarizing orwater-insolubilizing groups Hexadentates) attached. Se ValenceStabilizer #15: Macrocyclic ligands containing at least one 6- Four-, orSix-Membered Macrocyclics, membered heterocyclic ring. TheseMacrobicyclics, and Macropolycyclics heterocyclic rings provide seleniumbinding (including Catapinands, Cryptands, sites to valence stabilizethe central metal ion. Cyclidenes, and Sepulchrates) wherein all Otherselenol or selenoether binding sites can Binding Sites are composed ofSelenium also be included in the macrocyclic ligand, so and arecontained in a Combination of 6- long as the total number of bindingsites is four Membered Heterocyclic Rings and Selenol or six. Caninclude other hydrocarbon/ring or Selenoether Groups (Se—Se Tridentates,systems bound to this macrocyclic ligand, but Se—Se Tetradentates, orSe—Se they do not coordinate with the stabilized, high Hexadentates)valence metal ion. This ligand and/or attached, uncoordinatinghydrocarbon/rings may or may not have halogen or polarizing or water-insolubilizing groups attached. Se Valence Stabilizer #16:R—C(═Se)—CR′R″—C(═Se)—R″′ where R, R′, R″, 1,3-Diselenoketones(Diseleno-beta- and R″′ represent H, NH₂, or any organic ketonates),1,3,5-Triselenoketones, Bis(1,3- functional group wherein the number ofcarbon Diselenoketones), and Poly(1,3- atoms ranges from 0 to 40,optionally having Diselenoketones) (S—S Bidentates, S—S halogen orpolarizing or water- Tridentates, S—S Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. Se Valence Stabilizer #17:RR′—C═C(—Se⁻)(—Se⁻), where R and R′ represent 1,1-Diselenolates,Bis(1,1-diselenolates), H, NH₂ or any organic functional group whereinand Poly(1,1-diselenolates) (Se—Se the number of carbon atoms rangesfrom 0 to Bidentates and Se—Se Tetradentates) 40, optionally havinghalogen or polarizing or water-insolubilizing/solubilizing groupsattached. Ligand can also contain nonbinding N, O, S, or P atoms. SeValence Stabilizer #18: RR′N⁺═C(SeH)(SeH), where R and R′Diselenocarbamates, represent H, OH, SH, OR″ (R″ = C₁-C₃₀ alkyl orBis(diselenocarbamates), and aryl), SR″ (R″ = C₁-C₃₀ alkyl or aryl), NH₂or Poly(diselenocarbamates) (including N- any organic functional groupwherein the hydroxydiselenocarbamates and N- number of carbon atomsranges from 0 to 40, mercaptodiselenocarbamates) (Se—Se optionallyhaving halogen or polarizing or Bidentates, Se—Se Tridentates, and Se—Sewater-insolubilizing/solubilizing groups Tetradentates) attached. Ligandcan also contain nonbinding N, O, S, or P atoms. Se Valence Stabilizer#19: (O═)P(—Se—R)(—Se—R′)(—Se—R″) or (Se═)P(—Se— TriselenophosphoricAcids R)(—Se—R′)(—O—R″), where R, R′, and R″ (PhosphorotriselenoicAcids), represent H, NH₂ or any organic functionalBis(triselenophosphoric acids), group wherein the number of carbon atomsPoly(triselenophosphoric acids), and ranges from 0 to 40, optionallyhaving halogen derivatives thereof (Se—Se Bidentates, Se—Se orpolarizing or water- Tridentates, Se—Se Tetradentates)insolubilizing/solubilizing groups attached. Ligand can also containnonbinding N, O, S, or P atoms. Se Valence Stabilizer #20:(O═)P(—Se—R)(—Se—R′)(—O—R″) or (Se═)P(—Se— Diselenophosphoric AcidsR)(—O—R′)(—O—R″), where R, R′, and R″ (Phosphorodiselenoic Acids),represent H, NH₂ or any organic functional Bis(diselenophosphoricacids), group wherein the number of carbon atoms Poly(diselenophosphoricacids), and ranges from 0 to 40, optionally having halogen derivativesthereof (Se—Se Bidentates, Se—Se or polarizing or water- Tridentates,Se—Se Tetradentates) insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. Se Valence Stabilizer#21: (Se═)P(—Se—R)(—Se—R′)(—Se—R″), where R, R′, TetraselenophosphoricAcids and R″ represent H, NH₂ or any organic (PhosphorotetraselenoicAcids), functional group wherein the number of carbonBis(tetraselenophosphoric acids), atoms ranges from 0 to 40, optionallyhaving Poly(tetraselenophosphoric acids), and halogen or polarizing orwater- derivatives thereof (Se—Se Bidentates, Se—Seinsolubilizing/solubilizing groups attached. Tridentates, Se—SeTetradentates) Ligand can also contain nonbinding N, O, S, or P atoms.Se Valence Stabilizer #22: R—Se—C(═Se)—O—R′ or R—Se—C(═O)—Se—R′ forDiselenocarbonates, Triselenocarbonates, diselenocarbonates, andR—Se—C(═Se)—Se—R′ for Bis(diselenocarbonates), and triselenocarbonates,where R, and R′ represent Bis(triselenocarbonates), (Se—Se Bidentates H,NH₂ or any organic functional group wherein and Se—Se Tetradentates) thenumber of carbon atoms ranges from 0 to 40, optionally having halogen orpolarizing or water-insolubilizing/solubilizing groups attached. Ligandcan also contain nonbinding N, O, S, or P atoms. Se Valence Stabilizer#23: Selenocyanates bound directly to the high Selenocyanates (SeMonodentates) valence metal ion. Se Valence Stabilizer #24: Selenolates(HSe—R, HSe—R—SeH, etc.), where R Selenolates (Se Monodentates) and R′represent H or any organic functional group wherein the number of carbonatoms ranges from 0 to 35, optionally having halogen or polarizing orwater- insolubilizing/solubilizing groups attached. MiscellaneousValence Stabilizer #1: Dialkenes or bicyclic or tricyclic hydrocarbonsDiene or bicyclic or tricyclic hydrocarbon bound directly to the highvalence metal ion. ligands Miscellaneous Valence Stabilizer #2: Cyanideand cyanate and related ligands bound Cyanide and related ligandsdirectly to the high valence metal ion. Miscellaneous Valence Stabilizer#3: Carbonyl (—CO) ligands bound directly to the Carbonyl ligands highvalence metal ion. Miscellaneous Valence Stabilizer #4: Halogen (X)atoms bound directly to the high Halogen ligands valence metal ion.Miscellaneous Valence Stabilizer #5: Hydroxo and oxo ligands bounddirectly to the Hydroxo and Oxo Ligands high valence metal ion.

N Valence Stabilizer #1a: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates or N—N Tetradentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: pentaazacyclodecane ([10]aneN₅);pentaazacycloundecane ([11]aneN₅); pentaazacyclododecane ([12]aneN₅);pentaazacyclotridecane ([13]aneN₅); pentazaacyclotetradecane([14]aneN₅); pentaazacyclopentadecane ([15]aneN₅);pentaazacyclodecatriene ([10]trieneN₅); pentaazacycloundecatriene([11]trieneN₅); pentaazacyclododecatriene ([12]trieneN₅);pentaazacyclotridecatriene ([13]trieneN₅); pentazaacyclotetradecatriene([14]trieneN₅); and pentaazacyclopentadecatriene ([15]trieneN₅).

N Valence Stabilizer #1b: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:heptaazacyclotetradecane ([14]aneN₇); heptaazacyclopentadecane([15]aneN₇); heptaazacyclohexadecane ([16]aneN₇);heptaazacycloheptadecane ([17]aneN₇); heptaazacyclooctadecane([18]aneN₇); heptaazacyclononadecane ([19]aneN₇); heptaazacycloeicosane([20]aneN₇); heptaazacycloheneicosane ([21]aneN₇);heptaazacyclotetradecatriene ([14]trieneN₇);heptaazacyclopentadecatriene ([15]trieneN₇); heptaazacyclohexadecatriene([16]trieneN₇); heptaazacycloheptadecatriene ([17]trieneN₇);heptaazacyclooctadecatriene ([18]trieneN₇); heptaazacyclononadecatriene([19]trieneN₇); heptaazacycloeicosatriene ([20]trieneN₇); andheptaazacycloheneicosatriene ([21]trieneN₇).

N Valence Stabilizer #1c: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofnitrogen (usually amine or imine groups) and are not contained incomponent heterocyclic rings (N—N Tridentates, N—N Tetradentates, or N—NHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:nonaazacyclooctadecane ([18]aneN₉); nonaazacyclononadecane ([19]aneN₉);nonaazacycloeicosane ([20]aneN₉); nonaazacycloheneicosane ([21]aneN₉);nonaazacyclodocosane ([22]aneN₉); nonaazacyclotricosane ([23]aneN₉);nonaazacyclotetracosane ([24]aneN₉); nonaazacyclopentacosane([25]aneN₉); nonaazacyclohexacosane ([26]aneN₉); nonaazacycloheptacosane([27]aneN₉); nonaazacyclooctadecatetradiene ([18]tetradieneN₉);nonaazacyclononadecatetradiene ([19]tetradieneN₉);nonaazacycloeicosatetradiene ([20]tetradieneN₉);nonaazacycloheneicosatetradiene ([21]tetradieneN₉);nonaazacyclodocosatetradiene ([22]tetradieneN₉);nonaazacyclotricosatetradiene ([23]tetradieneN₉);nonaazacyclotetracosatetradiene ([24]tetradieneN₉);nonaazacyclopentacosatetradiene ([25]tetradieneN₉);nonaazacyclohexacosatetradiene ([26]tetradieneN₉); andnonaazacycloheptacosatetradiene ([27]tetradieneN₉).

N Valence Stabilizer #2a: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of nitrogen and are contained in component 5-memberedheterocyclic rings (N—N Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: pentaphyrins (pentapyrroles); sapphyrins; smaragdyrins;pentaoxazoles; pentaisooxazoles; pentathiazoles; pentaisothiazoles;pentaazaphospholes; pentaimidazoles; pentapyrazoles; pentaoxadiazoles;pentathiadiazoles; pentadiazaphospholes; pentatriazoles;pentaoxatriazoles; and pentathiatriazoles.

N Valence Stabilizer #2b: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of nitrogen and are contained in component 5-memberedheterocyclic rings (N—N Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: heptaphyrins (heptapyrroles); heptaoxazoles;heptaisooxazoles; heptathiazoles; heptaisothiazoles; heptaazaphospholes;heptaimidazoles; heptapyrazoles; heptaoxadiazoles; heptathiadiazoles;heptadiazaphospholes; heptatriazoles; heptaoxatriazoles; andheptathiatriazoles.

N Valence Stabilizer #3a: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tridentates or N—NTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:superphthalocyanine; supernaphthalocyanine; diazapentaphyrins;tetraazapentaphyrins; pentaazapentaphyrins; diazapentapyrazoles;tetraazapentapyrazoles; pentaazapentapyrazoles; diazapentaimidazoles;tetraazapentaimidazoles; and pentaazapentaimidazoles.

N Valence Stabilizer #3b: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazaheptaphyrins; tetraazaheptaphyrins;hexaazaheptaphyrins; diazaheptapyrazoles; tetraazaheptapyrazoles;hexaazaheptapyrazoles; diazaheptaimidazoles; tetraazaheptaimidazoles;and hexaazaheptaimidazoles.

N Valence Stabilizer #3c: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all nine binding sites arecomposed of nitrogen and are contained in a combination of 5-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazanonaphyrins; tetraazanonaphyrins; hexaazanonaphyrins;diazanonapyrazoles; tetraazanonapyrazoles; hexaazanonapyrazoles;diazanonaimidazoles; tetraazanonaimidazoles; and hexaazanonaimidazoles.

N Valence Stabilizer #4a: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of nitrogen and are contained in component 6-memberedheterocyclic rings (N—N Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: cyclopentapyridines; cyclopentaoxazines;cyclopentathiazines; cyclopentaphosphorins; cyclopentaquinolines;cyclopentapyrazines; cyclopentapyridazines; cyclopentapyrimidines;cyclopentaoxadiazines; cyclopentathiadiazines;cyclopentadiazaphosphorins cyclopentaquinoxalines; cyclopentatriazines;cyclopentathiatriazines; and cyclopentaoxatriazines.

N Valence Stabilizer #4b: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of nitrogen and are contained in component 6-memberedheterocyclic rings (N—N Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: cycloheptapyridines; cycloheptaoxazines;cycloheptathiazines; cycloheptaphosphorins; cycloheptaquinolines;cycloheptapyrazines; cycloheptapyridazines; cycloheptapyrimidines;cycloheptaoxadiazines; cycloheptathiadiazines;cycloheptadiazaphosphorins cycloheptaquinoxalines; cycloheptatriazines;cycloheptathiatriazines; and cycloheptaoxatriazines.

N Valence Stabilizer #5a: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tridentates or N—NTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diazacyclopentapyridines; tetraazacyclopentapyridines;diazacyclopentaquinolines; tetraazacyclopentaquinolines;diazacyclopentapyrazines; tetraazacyclopentapyrazines;diazacyclopentapyridazines; tetraazacyclopentapyridazines;diazacyclopentapyrimidines; tetraazacyclopentapyrimidines;diazacyclopentatriazines; and tetraazacyclopentatriazines.

N Valence Stabilizer #5b: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazacycloheptapyridines; tetraazacycloheptapyridines;diazacycloheptaquinolines; tetraazacycloheptaquinolines;diazacycloheptapyrazines; tetraazacycloheptapyrazines;diazacycloheptapyridazines; tetraazacycloheptapyridazines;diazacycloheptapyrimidines; tetraazacycloheptapyrimidines;diazacycloheptatriazines; and tetraazacycloheptatriazines.

N Valence Stabilizer #5c: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all nine binding sites arecomposed of nitrogen and are contained in a combination of 6-memberedheterocyclic rings and amine or imine groups (N—N Tridentates, N—NTetradentates, or N—N Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diazacyclononapyridines; tetraazacyclononapyridines;diazacyclononaquinolines; tetraazacyclononaquinolines;diazacyclononapyrazines; tetraazacyclononapyrazines;diazacyclononapyridazines; tetraazacyclononapyridazines;diazacyclononapyrimidines; tetraazacyclononapyrimidines;diazacyclononatriazines; and tetraazacyclononatriazines.

N Valence Stabilizer #6: Examples of silylamines and silazanes (NMonodentates, N—N Bidentates, N—N Tridentates, N—N Tetradentates, andN—N Hexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:trisilylamine; N-methyldisilazane (disilylmethylamine);N,N-dimethylsilylamine; (silyldimethylamine); tris(trimethylsilyl)amine;triethylsilylamine (triethylaminosilane) (triethylsilazane);N-ethyltriethylsilylamine (triethylN-ethylaminosilane);di-tert-butylsilanediamine (di-tert-butyldiaminosilane);bis(methylamino)diethylsilane; tris(dimethylamino)ethylsilane;hexamethyldisilazane; N-methylhexaphenyldisilazane;hexamethylcyclotrisilazane; and octaphenylcyclotetrasilazane. [Note:silylamines and silazanes are notably weaker ligands than theircarbonaceous derivatives, although replacement of one or two SiR₃ groupswith CR₃ will enhance the donor power of the ligand. Thus, N(CR₃)₂(SiR₃)is a better ligand than N(CR₃)(SiR₃)₂, etc.]

N Valence Stabilizer #7: Examples of guanidines, diguanidines, andpolyguanidines (N—N bidentates, N—N tridentates, N—N tetradentates, andN—N hexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: guanidine;methylguanidine; ethylguanidine; isopropylguanidine; butylguanidine;benzylguanidine; phenylguanidine; tolylguanidine; naphthylguanidine;cyclohexylguanidine; norbornylguanidine; adamantylguanidine;dimethylguanidine; diethylguanidine; dii sopropylguanidine;dibutylguanidine; dibenzylguanidine; diphenylguanidine;ditolylguanidine; dinaphthylguanidine; dicyclohexylguanidine;dinorbornylguanidine; diadamantylguanidine; ethylenediguanidine;propylenediguanidine; tetramethylenediguanidine;pentamethylenediguanidine; hexamethylenediguanidine;heptamethylenediguanidine; octamethylenediguanidine;phenylenediguanidine; piperazinediguanidine; oxalyldiguanidine;malonyldiguanidine; succinyldiguanidine; glutaryldiguanidine;adipyldiguanidine; pimelyldiguanidine; suberyldiguanidine;phthalyldiguanidine; benzimidazoleguanidine; aminoguanidine;nitroaminoguanidine; dicyandiamide (cyanoguanidine); dodecylguanidine;and nitrovin.

N Valence Stabilizer #8: Examples of phosphonitrile amides andbis(phosphonitrile amides) (N—N Bidentates and N—N Tetradentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: phosphononitrile amide;N-phenylphosphonitrile amide; N-benzylphosphonitrile amide;N-cyclohexylphosphonitrile amide; N-norbornylphosphonitrile amide;N,N′-diphenylphosphonitrile amide; N,N′-dibenzylphosphonitrile amide;N,N′-dicyclohexylphosphonitrile amide; andN,N′-dinorbornylphosphonitrile amide. [Note: the phosphite (P⁺³) valenceof the phosphorus atom makes stabilizization of high valence metal ionsmuch more difficult, though still possible.]

N Valence Stabilizer #9: Examples of phosphonimidic diamides,bis(phosphonimidic diamides), and poly(phosphonimidic diamides) (N—Nbidentates and N—N tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphonimidic diamide; N-benzylphosphonimidic diamide;N-phenylphosphonimidic diamide; N-cyclohexylphosphonimidic diamide;N-norbornylphosphonimidic diamide; N,N-dibenzylphosphonimidic diamide;N,N-diphenylphosphonimidic diamide; N,N-dicyclohexylphosphonimidicdiamide; and N,N-dinorbornylphosphonimidic diamide. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.]

N Valence Stabilizer #10: Examples of phosphonamidimidic acid,phosphonamidimidothioic acid, bis(phosphonamidimidic acid),bis(phosphonamidimidothioic acid), poly(phosphonamidimidic acid),poly(phosphonamidimidothioic acid), and derivatives thereof (N—NBidentates, and N—N Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphonamidimidic acid, phosphonamidimidothioic acid;O-phenylphosphonamidimidic acid; O-benzylphosphonamidimidic acid;O-cyclohexylphosphonamidimidic acid; O-norbornylphosphonamidimidic acid;S-phenylphosphonamidimidothioic acid; S-benzylphosphonamidimidothioicacid; S-cyclohexylphosphonamidimidothioic acid; andS-norbornylphosphonamidimidothioic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

N Valence Stabilizer #11: Examples of pyridinaldimines,bis(pyridinaldimines), and poly(pyridinaldimines) (N—N Bidentates, N—NTridentates, and N—N Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: pyridylideneaniline [N-(pyridylmethylene)benzenamine]; and(2-pyridyl)benzylideneaniline.

N Valence Stabilizer #12: Examples of hydrazones, bis(hydrazones), andpoly(hydrazones) (N Monodentates, N—N Bidentates, N—N Tridentates, andN—N Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:acetaldehyde hydrazone; acetaldehyde phenylhydrazone; acetone hydrazone;acetone phenylhydrazone; pinacolone hydrazone; pinacolonephenylhydrazone; benzaldehyde hydrazone; benzaldehyde phenylhydrazone;naphthaldehyde hydrazone; naphthaldehyde phenylhydrazone; norbornanonehydrazone; norbornanone phenylhydrazone; camphor hydrazone; camphorphenylhydrazone; nopinone hydrazone; nopinone phenylhydrazine;2-pyridinaldehyde hydrazone; 2-pyridinealdehyde phenylhydrazone;salicylaldehyde hydrazone; salicylaldehyde phenylhydrazone;quinolinaldehyde hydrazone; quinolinaldehyde phenylhydrazone; isatindihydrazone; isatin di(phenylhydrazone); camphorquinone dihydrazone;camphotquinone di(phenylhydrazone); and 2-hydrazinobenzimidazolehydrazone.

N Valence Stabilizer #13: Examples of azo compounds without chelatesubstitution at the ortho-(for aryl) or alpha- or beta- (for alkyl)positions, bis(azo compounds), or poly(azo compounds) (N Monodentates,N—N Bidentates, or N—N Tridentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: azobenzene (diphenyldiazene); p-diaminoazobenzene;p-dimethylaminoazobenzene (butter yellow); methyl orange; Fast GarnetGBC (4′-amino-2,3′-dimethylazobenzene) [Note: non-bonding methyl groupin the o-position.]; and Alizarin Yellow R. [Note: azo compounds withoutchelate substitution at the ortho- (for aryl) or beta- (for alkyl)positions tend to stabilize lower oxidation states in metal ions.]

N Valence Stabilizer #14: Examples of formazans, bis(formazans), andpoly(formazans) without ortho-hydroxy, carboxy, thiol, mercapto, amino,or hydrazido substitution (N—N Bidentates, N—N Tetradentates, and N—NHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:1,3,5-triphenylformazan; and 1,3,5-naphthylformazan.

N Valence Stabilizer #15: Examples of hydramides (N—N Bidentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: hydrobenzamide; hydronaphthamide;and hydrosalicylamide.

N Valence Stabilizer #16: Examples of azines (including ketazines),bis(azines), and poly(azines) without ortho-hydroxy, carboxy, thiol,mercapto, amino, or hydrazido substitution (N—N Bidentates, N—NTetradentates, and N—N Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: benzalazine; naphthalazine; cyclohexanonazine; andnorbornonazine.

N Valence Stabilizer #17: Examples of Schiff Bases with one Imine (C═N)Group and without ortho- (for aryl constituents) or alpha- or beta- (foralkyl constituents) hydroxy, carboxy, carbonyl, thiol, mercapto,thiocarbonyl, amino, imino, oximo, diazeno, or hydrazido substitution (NMonodentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N-(Benzaldehydo)isopropylamine; N-(Naphthaldehydo)isopropylamine;N-(Acetophenono)isopropylamine; N-(Propiophenono)isopropylamine;N-(Benzaldehydo)cyclohexylamine; N-(Naphthaldehydo)cyclohexylamine;N-(Acetophenono)cyclohexylamine; N-(Propiophenono)cyclohexylamine;N-(Benzaldehydo)aniline (BAAN); N-(Naphthaldehydo)aniline;N-(Acetophenono)aniline; N-(Propiophenono)aniline;N-(Benzaldehydo)aminonorbornane; N-(Naphthaldehydo)aminonorbornane;N-(Acetophenono)aminonorbornane; N-(Propiophenono)aminonorbornane;(Vanillino)anisidine; (Cinnamaldehydo)anisidine;N-(o-carboxycinnamaldehydo)aniline; N-(cinnamaldehydo)aniline;N-(cinnamaldehydo)m- or p-anisidine; and N-(o-carboxycinnamaldehydo)m-or p-anisidine.

N Valence Stabilizer #18: Examples of isocyanide and cyanamide andrelated ligands (N Monodentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: isocyanate (—NCO); isothiocyanate (—NCS); isoselenocyanate (—NCSe);and cyanamide (—NCN). [Note: the nitrogen atom is directly complexed tothe high valence metal ion.]

N Valence Stabilizer #19: Examples of nitrosyls and nitrites and relatedligands (N Monodentates) that meet the requirements for use as “narrowband” valence stabilizers for Ce⁺⁴ include, but are not limited to:nitrosyl (—NO); thionitrosyl (—NS); nitrite (—NO₂); thionitrite(sulfinylamide)(thiazate)(—NSO); nitrosamine (═NN═O); thionitrosamine(═NN═S); nitramine (═NNO₂); and thionitramine (═NNS₂) ligands.

N Valence Stabilizer #20: Examples of nitriles, dinitriles, andpolynitriles (N Monodentates, N—N Bidentates, N—N Tridentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: benzonitrile; naphthonitrile;cyanonaphthalene; cyclohexyl nitrile; cyanopyridine; cyanopurine;cyanophenol; cyanothiophenol; adamantane nitrile; norbornyl nitrile;cinnamonitrile; dicyanobenzene; dicyanobutene; dicyanoimidazole;dicyanopyridine; cyanotolunitrile; tetracyanoethylene (TCNE);tetracyanoquinodimethane (TCNQ); diethylaminopropionitrile (deapn), andpolyacrylonitriles.

N Valence Stabilizer #21: Examples of azide ligands (N monodentates)that meet the s requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to: azide (—N₃) ions;methyl azide; ethyl azide; phenyl azide; diphenyltriazene; and phenylsulfonyl azide.

S Valence Stabilizer #1: Examples of monothioethers (S monodentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: hydrogen sulfide, dimethylsulfide, diethyl sulfide, dioctyl sulfide, diphenyl sulfide,dicyclohexyl sulfide, tetramethylene sulfide (tetrahydrothiophene, tht),trimethylene sulfide, dimethylene sulfide (ethylene sulfide),pentamethylene sulfide, 1,4-thioxane, oxathiolane, cyclohexene sulfide,cyclooctene sulfide, benzotetrahydrothiophene, dibenzothiophene,naphthotetrahydrothiophene, and thiabicycloheptane.

S Valence Stabilizer #2: Examples of disulfides (S monodentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: methyl disulfide, ethyl disulfide,phenyl disulfide, nitrophenide, and 1,2-dithiacyclohexane.

S Valence Stabilizer #3: Examples of dithioethers (S monodentates or S—Sbidentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to: 1,3-dithiane,1,4-dithiane, benzodithiane, dibenzodithiane, naphthodithiane,2,5-dithiahexane (dth); 3,6-dithiaoctane (dto);2,5-dimethyl-3,6-dithiaoctane; 3,7-dithianonane; 2,6-dithiaheptane;1,6-diphenyl-2,5-dithiahexane; 1,4-diphenyl-1,4-dithiabutane;1,3-dithiolane; 1,4-dithiane (1,4-dithiacyclohexane);1,4-dithiacycloheptane (dtch); 1,5-dithiacyclooctane (dtco);o-phenylenebis(2-thiapropane); o-phenylenebis(2-thiabutane);2,2′-(thiamethyl)biphenyl, and 2,2′-(thiaethyl)biphenyl.

S Valence Stabilizer #4: Examples of trithioethers (S monodentates, S—Sbidentates, or S—S tridentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 1,3,5-trithiane; 1,3,5-tris(methylthia)cyclohexane;1,3,5-tris(ethylthia)cyclohexane; 1,3,5-tris(phenylthia)cyclohexane;2,5,8-trithianonane; 3,6,9-trithiaundecane; and 2,6,10-trithiaundecane.

S Valence Stabilizer #5: Examples of tetrathioethers (S monodentates,S—S bidentates, S—S tridentates, or S—S tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 1,4,10,13-tetrathiatridecane;2,6,10,14-tetrathiapentadecane; 2,5,8,11-tetrathiadodecane;2,5,9,12-ttetrathiatridecane; 2,6,9,13-tetrathiatetradecane;1,4-(o-thiomethyl)phenyl-1,4-dithiabutane;1,5-(o-thiomethyl)phenyl-1,5-dithiapentane;1,6-(o-thiomethyl)phenyl-1,6-dithiahexane;1,4-(o-thiomethyl)phenyl-1,4-dithiabut-2-ene; and polythioethers.

S Valence Stabilizer #6: Examples of hexathioethers (S monodentates, S—Sbidentates, S—S tridentates, S—S tetradentates, or S—S hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:tri(2-((o-thiomethyl)phenyl)ethyl)amine; andtri((o-thiomethyl)phenyl)methylamine.

S Valence Stabilizer #7a: Examples of 5-membered heterocyclic ringscontaining one sulfur atom (S monodentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: dihydrothiophene, thiophene, thiazole, thiapyrroline,thiaphospholene, thiaphosphole, oxathiole, thiadiazole, thiatriazole,benzodihydrothiophene, benzothiophene, benzothiazole,benzothiaphosphole, dibenzothiophene, and naphthothiophene.

S Valence Stabilizer #7b: Examples of 5-membered heterocyclic ringscontaining two sulfur atoms (S monodentates or S—S bidentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiole, benzodithiole, andnaphthodithiole.

S Valence Stabilizer #8a: Examples of 6-membered heterocyclic ringscontaining one sulfur atom (S monodentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: dihydrothiopyran, thiopyran, thiazine, thiadiazine,thiaphosphorin, thiadiphosphorin, oxathiin, benzothiopyran,dibenzothiopyran, and naphthothiopyran.

S Valence Stabilizer #8b: Examples of 6-membered heterocyclic ringscontaining two sulfur atoms (S monodentates or S—S bidentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dihydrodithiin, dithiin, benzodithiin,dibenzodithiin (thianthrene), and naphthodithiin.

S Valence Stabilizer #9a: Examples of 5-membered heterocyclic ringscontaining one sulfur atom and having at least one additional sulfuratom binding site not contained in a ring (S Monodentates, S—SBidentates, S—S Tridentates, S—S Tetradentates, or S—S Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2,5-dimercapto-2,5-dihydrothiophene;2,5-bis(thiomethyl)-2,5-dihydrothiophene;2,5-bis(2-thiophenyl)-2,5-dihydrothiophene; 2,5-dimercaptothiophene;2,5-bis(thiomethyl)thiophene; 2,5-bis(2-thiophenyl)thiophene;2,5-dimercatothiazole; 2,5-bis(thiomethyl)thiazole;2,5-bis(2-thiophenyl)thiazole; 2,5-dimercapto-1,3,4-thiadiazole[bismuththiol]; 2-mercaptothianaphthene; 7-(thiomethyl)thianaphthene;1,8-dimercaptodibenzothiophene; 2-mercaptobenzothiazole;2-mercapro-1,3,4-thiadiazole; 2-amino-5-mercapto-1,3,4-thiadiazole;2,5-bis(alkylthio)-1,3,4-thiadiazole; and 7-(thiomethyl)benzothiazole.

S Valence Stabilizer #9b: Examples of 5-membered heterocyclic ringscontaining two sulfur atoms and having at least one additional sulfuratom binding site not contained in a ring (S Monodentates, S—SBidentates, S—S Tridentates, S—S Tetradentates, or S—S Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-mercapto-1,3-dithiole;2-(dimercaptomethyl)-1,3-dithiole; 4,5-dimercapto-1,3-dithiole;4,5-bis(2-thiophenyl)-1,3-dithiole; 2-mercaptobenzodithiole; and7-mercaptobenzodithiole.

S Valence Stabilizer #10a: Examples of 6-membered heterocyclic ringscontaining one sulfur atom and having at least one additional sulfuratom binding site not contained in a ring (S Monodentates, S—SBidentates, S—S Tridentates, S—S Tetradentates, or S—S Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2,6-dimercapto-2,5-dihydrothiopyran;2,6-bis(thiomethyl)-2,5-dihydrothiopyran;2,6-bis(2-thiophenyl)-2,5-dihydrothiopyran; 2,6dimercaptothiopyran;2,6-bis(thiomethyl)thiopyran; 2,6-bis(2-thiophenyl)thiopyran;2,6-dimercaptothiazine; 2,6-bis(thiomethyl)thiazine;2,6-bis(2-thiophenyl)thiazine; 2,6-dimercapto-1,3,5-thiadiazine;2-mercapto-1-benzothiopyran; 8-mercapto-1-benzothiopyran; and1,9-dimercaptodibenzothiopyran.

S Valence Stabilizer #10b: Examples of 6-membered heterocyclic ringscontaining two sulfur atoms and having at least one additional sulfuratom binding site not contained in a ring (S Monodentates, S—SBidentates, S—S Tridentates, S—S Tetradentates, or S—S Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-mercapto-1,4-dithiin;2,6-dimercapto-1,4-dithiin; 2,6-bis(2-thiophenyl)-1,4-dithiin;2,3-dimercapto-1,4-benzodithiin; 5,8-dimercapto-1,4-benzodithiin;1,8-dimercaptothianthrene; and 1,4,5,8-tetramercaptothianthrene.

S Valence Stabilizer #11a: Examples of 5-membered heterocyclic ringscontaining one sulfur atom and having at least one additional sulfuratom binding site contained in a ring (S Monodentates, S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2,2′-bi-2,5-dihydrothiophene;2,2′,2″-tri-2,5-dihydrothiophene; 2,2′-bithiophene;2,2′,2″-trithiophene; 2,2′-bithiazole; 5,5′-bithiazole;2,2′-bioxathiole; 2,2′-bi-1,3,4-thiadiazole; 2,2′-bithianaphthene;2,2′-bibenzothiazole; 1,1′-bis(dibenzothiophene); and polythiophenes.

S Valence Stabilizer #11b: Examples of 5-membered heterocyclic ringscontaining two sulfur atoms and having at least one additional sulfuratom binding site contained in a ring (S Monodentates, S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2,2′-bi-1,3-dithiole; 4,4′-bi-1,3-dithiole;7,7′-bi-1,2-benzodithiole; 3,3′-bi-1,2-benzodithiole; andtetrathiofulvalene.

S Valence Stabilizer #12a: Examples of 6-membered heterocyclic ringscontaining one sulfur atom and having at least one additional sulfuratom binding site contained in a ring (S Monodentates, S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2,2′-bi-2,5-dihydrothiopyran;2,2′,2″-tri-2,5-dihydrothiopyran; 2,2′-bithiopyran;2,2′,2″-trithiopyran; 2,2′-bi-1,4-thiazine; 2,2′-bi-1,3,5-thiadiazine;2,2′-bi-1-benzothiopyran; and 1,1′-bis(dibenzothiopyran)

S Valence Stabilizer #12b: Examples of 6-membered heterocyclic ringscontaining two sulfur atoms and having at least one additional sulfuratom binding site contained in a ring (S Monodentates, S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2,2′-bi-1,4-dithiin; 2,2′-bi-1,3-dithiin;5,5′-bi-1,4-benzodithiin; 2,2′-bi-1,3-benzodithiin; and1,1′-bithianthrene.

S Valence Stabilizer #13a: Examples of two-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein both binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Bidentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: dithiacyclobutane ([4]aneS₂); dithiacyclopentane([5]aneS₂); dithiacyclohexane ([6]aneS₂); dithiacycloheptane ([7]aneS₂);dithiacyclooctane ([8]aneS₂); dithiacyclobutene ([4]eneS₂);dithiacyclopentene ([5]eneS₂); dithiacyclohexene ([6]eneS₂);dithiacycloheptene ([7]eneS₂); dithiacyclooctene ([8]eneS₂);dithiacyclobutadiene ([4]dieneS₂); dithiacyclopentadiene ([5]dieneS₂);dithiacyclohexadiene ([6]dieneS₂); dithiacycloheptadiene ([7]dieneS₂);and dithiacyclooctadiene ([8]dieneS₂).

S Valence Stabilizer #13b: Examples of three-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trithiacyclohexane ([6]aneS₃);trithiacycloheptane ([7]aneS₃); trithiacyclooctane ([8]aneS₃);trithiacyclononane ([9]aneS₃); trithiacyclodecane ([10]aneS₃);trithiacycloundecane ([11]aneS₃); trithiacyclododecane ([12]aneS₃);trithiacyclohexene ([6]eneS₃); trithiacycloheptene ([7]eneS₃);trithiacyclooctene ([8]eneS₃); trithiacyclononene ([9]eneS₃);trithiacyclodecene ([10]eneS₃); trithiacycloundecene ([11]eneS₃);trithiacyclododecene ([12]eneS₃); trithiacyclohexatriene ([6]trieneS₃);trithiacycloheptatriene ([7]trieneS₃); trithiacyclooctatriene([8]trieneS₃); trithiacyclononatriene ([9]trieneS₃);trithiacyclodecatriene ([10]trieneS₃); trithiacycloundecatriene([11]trieneS₃); and trithiacyclododecatriene ([12]trieneS₃).

S Valence Stabilizer #13c: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetrathiacyclooctane ([8]aneS₄);tetrathiacyclononane ([9]aneS₄); tetrathiacyclodecane ([10]aneS₄);tetrathiacycloundecane ([11]aneS₄); tetrathiacyclododecane ([12]aneS₄);tetrathiacyclotridecane ([13]aneS₄); tetrathiacyclotetradecane([14]aneS₄); tetrathiacyclopentadecane ([15]aneS₄);tetrathiacyclohexadecane ([16]aneS₄); tetrathiacycloheptadecane([17]aneS₄); tetrathiacyclooctadecane ([18]aneS₄);tetrathiacyclononadecane ([19]aneS₄); tetrathiacycloeicosane([20]aneS₄); tetrathiacyclooctadiene ([8]dieneS₄);tetrathiacyclononadiene ([9]dieneS₄); tetrathiacyclodecadiene([10]dieneS₄); tetrathiacycloundecadiene ([11]dieneS₄);tetrathiacyclododecadiene ([12]dieneS₄); tetrathiacyclotridecadiene([13]dieneS₄); tetrathiacyclotetradecadiene ([14]dieneS₄);tetrathiacyclopentadecadiene ([15]dieneS₄); tetrathiacyclohexadecadiene([16]dieneS₄); tetrathiacycloheptadecadiene ([17]dieneS₄);tetrathiacyclooctadecadiene ([18]dieneS₄); tetrathiacyclononadecadiene([19]dieneS₄); tetrathiacycloeicosadiene ([20]dieneS₄);tetrathiacyclooctatetradiene ([8]tetradieneS₄);tetrathiacyclononatetradiene ([9]tetradieneS₄);tetrathiacyclodecatetradiene ([10]tetradieneS₄);tetrathiacycloundecatetradiene ([11]tetradieneS₄);tetrathiacyclododecatetradiene ([12]tetradieneS₄);tetrathiacyclotridecatetradiene ([13]tetradieneS₄);tetrathiacyclotetradecatetradiene ([14]tetradieneS₄);tetrathiacyclopentadecatetradiene ([15]tetradieneS₄);tetrathiacyclohexadecatetradiene ([16]tetradieneS₄);tetrathiacycloheptadecatetradiene ([17]tetradieneS₄);tetrathiacyclooctadecatetradiene ([18]tetradieneS₄);tetrathiacyclononadecatetradiene ([19]tetradieneS₄); andtetrathiacycloeicosatetradiene ([20]tetradieneS₄).

S Valence Stabilizer #13d: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates or S—S Tetradentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: pentathiacyclodecane ([10]aneS₅);pentathiacycloundecane ([11]aneS₅); pentathiacyclododecane ([12]aneS₅);pentathiacyclotridecane ([13]aneS₅); pentathiacyclotetradecane([14]aneS₅); pentathiacyclopentadecane ([15]aneS₅);pentathiacyclodecatriene ([10]trieneS₅); pentathiacycloundecatriene([11]trieneS₅); pentathiacyclododecatriene ([12]trieneS₅);pentathiacyclotridecatriene ([13]trieneS₅);pentathiacyclotetradecatriene ([14]trieneS₅); andpentathiacyclopentadecatriene ([15]trieneS₅).

S Valence Stabilizer #13e: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:hexathiacyclododecane ([12]aneS₆); hexathiacyclotridecane ([13]aneS₆);hexathiacyclotetradecane ([14]aneS₆); hexathiacyclopentadecane([15]aneS₆); hexathiacyclohexadecane ([16]aneS₆);hexathiacycloheptadecane ([17]aneS₆); hexathiacyclooctadecane([18]aneS₆); hexathiacyclononadecane ([19]aneS₆); hexathiacycloeicosane([20]aneS₆); hexathiacycloheneicosane ([21]aneS₆); hexathiacyclodocosane([22]aneS₆); hexathiacyclotricosane ([23]aneS₆);hexathiacyclotetracosane ([24]aneS₆); hexathiacyclododecatriene([12]trieneS₆); hexathiacyclotridecatriene ([13]trieneS₆);hexathiacyclotetradecatriene ([14]trieneS₆);hexathiacyclopentadecatriene ([15]trieneS₆); hexathiacyclohexadecatriene([16]trieneS₆); hexathiacycloheptadecatriene ([17]trieneS₆);hexathiacyclooctadecatriene ([18]trieneS₆); hexathiacyclononadecatriene([19]trieneS₆); hexathiacycloeicosatriene ([20]trieneS₆);hexathiacycloheneicosatriene ([21]trieneS₆); hexathiacyclodocosatriene([22]trieneS₆); hexathiacyclotricosatriene ([23]trieneS₆); andhexathiacyclotetracosatriene ([24]trieneS₆).

S Valence Stabilizer #13f: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:heptathiacyclotetradecane ([14]aneS₇); heptathiacyclopentadecane([15]aneS₇); heptathiacyclohexadecane ([16]aneS₇);heptathiacycloheptadecane ([17]aneS₇); heptathiacyclooctadecane([18]aneS₇); heptathiacyclononadecane ([19]aneS₇);heptathiacycloeicosane ([20]aneS₇); heptathiacycloheneicosane([21]aneS₇); heptathiacyclotetradecatriene ([14]trieneS₇);heptathiacyclopentadecatriene ([15]trieneS₇);heptathiacyclohexadecatriene ([16]trieneS₇);heptathiacycloheptadecatriene ([17]trieneS₇);heptathiacyclooctadecatriene ([18]trieneS₇);heptathiacyclononadecatriene ([19]trieneS₇); heptathiacycloeicosatriene([20]trieneS₇); and heptathiacycloheneicosatriene ([21]trieneS₇).

S Valence Stabilizer #13g: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:octathiacyclohexadecane ([16]aneS₈); octathiacycloheptadecane([17]aneS₈); octathiacyclooctadecane ([18]aneS₈);octathiacyclononadecane ([19]aneS₈); octathiacycloeicosane ([20]aneS₈);octathiacycloheneicosane ([21]aneS₈); octathiacyclodocosane ([22]aneS₈);octathiacyclotricosane ([23]aneS₈); octathiacyclotetracosane([24]aneS₈); octathiacyclohexadecatetradiene ([16]tetradieneS₈);octathiacycloheptadecatetradiene ([17]tetradieneS₈);octathiacyclooctadecatetradiene ([18]tetradieneS₈);octathiacyclononadecatetradiene ([19]tetradieneS₈);octathiacycloeicosatetradiene ([20]tetradieneS₈);octathiacycloheneicosatetradiene ([21]tetradieneS₈);octathiacyclodocosatetradiene ([22]tetradienes₈);octathiacyclotricosatetradiene ([23]tetradieneS₈); andoctathiacyclotetracosatetradiene ([24]tetradieneS₈).

S Valence Stabilizer #13h: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:nonathiacyclooctadecane ([18]aneS₉); nonathiacyclononadecane([19]aneS₉); nonathiacycloeicosane ([20]aneS₉); nonathiacycloheneicosane([21]aneS₉); nonathiacyclodocosane ([22]aneS₉); nonathiacyclotricosane([23]aneS₉); nonathiacyclotetracosane ([24]aneS₉);nonathiacyclopentacosane ([25]aneS₉); nonathiacyclohexacosane([26]aneS₉); nonathiacycloheptacosane ([27]aneS₉);nonathiacyclooctadecatetradiene ([18]tetradieneS₉);nonathiacyclononadecatetradiene ([19]tetradieneS₉);nonathiacycloeicosatetradiene ([20]tetradieneS₉);nonathiacycloheneicosatetradiene ([21]tetradieneS₉);nonathiacyclodocosatetradiene ([22]tetradieneS₉);nonathiacyclotricosatetradiene ([23]tetradieneS₉);nonathiacyclotetracosatetradiene ([24]tetradieneS₉);nonathiacyclopentacosatetradiene ([25]tetradieneS₉);nonathiacyclohexacosatetradiene ([26]tetradieneS₉); andnonathiacycloheptacosatetradiene ([27]tetradieneS₉).

S Valence Stabilizer #13i: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol or thioether groups) and are not contained incomponent heterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:decathiacycloeicosane ([20]aneS₁₀); decathiacycloheneicosane([21]aneS₁₀); decathiacyclodocosane ([22]aneS₁₀); decathiacyclotricosane([23]aneS₁₀); decathiacyclotetracosane ([24]aneS₁₀);decathiacyclopentacosane ([25]aneS₁₀); decathiacyclohexacosane([26]aneS₁₀); decathiacycloheptacosane ([27]aneS₁₀);decathiacyclooctacosane ([28]aneS₁₀); decathiacyclononacosane([29]aneS₁₀); decathiacyclotriacontane ([30]aneS₁₀);decathiacycloeicosapentadiene ([20]pentadieneS₁₀);decathiacycloheneicosapentadiene ([21]pentadieneS₁₀);decathiacyclodocosapentadiene ([22]pentadieneS₁₀);decathiacyclotricosapentadiene ([23]pentadieneS₁₀);decathiacyclotetracosapentadiene ([24]pentadieneS₁₀);decathiacyclopentacosapentadiene ([25]pentadieneS₁₀);decathiacyclohexacosapentadiene ([26]pentadieneS₁₀);decathiacycloheptacosapentadiene ([27]pentadieneS₁₀);decathiacyclooctacosapentadiene ([28]pentadieneS₁₀);decathiacyclononacosapentadiene ([29]pentadieneS₁₀); anddecathiacyclotriacontapentadiene ([30]pentadieneS₁₀).

S Valence Stabilizer #14a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of sulfur and are contained in component 5-memberedheterocyclic rings (S—S Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tetrathiophenes; tetrathiazoles; tetrathiaphospholes;tetraoxathioles; tetrathiadiazoles; tetrathiatriazoles; andtetradithioles.

S Valence Stabilizer #14b: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of sulfur and are contained in component 5-memberedheterocyclic rings (S—S Tridentates or S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: pentathiophenes; pentathiazoles;pentathiaphospholes; pentaoxathioles; pentathiadiazoles;pentathiatriazoles; and pentadithioles.

S Valence Stabilizer #14c: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof sulfur and are contained in component 5-membered heterocyclic rings(S—S Tridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: hexathiophenes; hexathiazoles;hexathiaphospholes; hexaoxathioles; hexathiadiazoles; hexathiatriazoles;and hexadithioles.

S Valence Stabilizer #14d: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of sulfur and are contained in component 5-memberedheterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:heptathiophenes; heptathiazoles; heptathiaphospholes; heptaoxathioles;heptathiadiazoles; heptathiatriazoles; and heptadithioles.

S Valence Stabilizer #14e: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of sulfur and are contained in component 5-memberedheterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:octathiophenes; octathiazoles; octathiaphospholes; octaoxathioles;octatbiadiazoles; octathiatriazoles; and octadithioles.

S Valence Stabilizer #14f: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all nine binding sites arecomposed of sulfur and are contained in component 5-memberedheterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:nonathiophenes; nonathiazoles; nonathiaphospholes; nonaoxathioles;nonathiadiazoles; nonathiatriazoles; and nonadithioles.

S Valence Stabilizer #14g: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof sulfur and are contained in component 5-membered heterocyclic rings(S—S Tridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: decathiophenes; decathiazoles;decathiaphospholes; decaoxathioles; decathiadiazoles; decathiatriazoles;and decadithioles.

S Valence Stabilizer #15a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of sulfur and are contained in a combination of 5-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithiatetrathiophenes; tetrathiatetrathiophenes; dithiatetradithioles;and tetrathiatetradithioles.

S Valence Stabilizer #15b: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of sulfur and are contained in a combination of 5-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates or S—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithiapentathiophenes; tetrathiapentathiophenes;dithiapentadithioles; and tetrathiapentadithioles.

S Valence Stabilizer #15c: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof sulfur and are contained in a combination of 5-membered heterocyclicrings and thiol, thioether, or thioketo groups (S—S Tridentates, S—STetradentates, or S—S Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dithiahexaathiophenes; trithiahexathiophenes;dithiahexadithioles; and trithiahexadithioles.

S Valence Stabilizer #15d: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of sulfur and are contained in a combination of 5-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiaheptathiophenes;tetrathiaheptathiophenes; dithiaheptadithioles; andtetrathiaheptadithioles.

S Valence Stabilizer #15e: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of sulfur and are contained in a combination of 5-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiaoctathiophenes;tetrathiaoctathiophenes; dithiaoctadithioles; andtetrathiaoctadithioles.

S Valence Stabilizer #15f: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all nine binding sites arecomposed of sulfur and are contained in a combination of 5-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trithianonathiophenes;hexathianonathiophenes; trithianonadithioles; and hexathianonadithioles.

S Valence Stabilizer #15g: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof sulfur and are contained in a combination of 5-membered heterocyclicrings and thiol, thioether, or thioketo groups (S—S Tridentates, S—STetradentates, or S—S Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dithiadecathiophenes; pentathiadecathiophenes;dithiadecadithioles; and pentathiadecadithioles.

S Valence Stabilizer #16a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of sulfur and are contained in component 6-memberedheterocyclic rings (S—S Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tetrathiopyrans; tetrathiazines; tetrathiaphosphorins;tetrathiadiphosphorins; tetraoxathiins; and tetradithiins.

S Valence Stabilizer #16b: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of sulfur and are contained in component 6-memberedheterocyclic rings (S—S Tridentates or S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: pentathiopyrans; pentathiazines;pentathiaphosphorins; pentathiadiphosphorins; pentaoxathiins; andpentadithiins.

S Valence Stabilizer #16c: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof sulfur and are contained in component 6-membered heterocyclic rings(S—S Tridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: hexathiopyrans; hexathiazines;hexathiaphosphorins; hexathiadiphosphorins; hexaoxathiins; andhexadithiins.

S Valence Stabilizer #16d: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of sulfur and are contained in component 6-memberedheterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:heptathiopyrans; heptathiazines; heptathiaphosphorins;heptathiadiphosphorins; heptaoxathiins; and heptadithiins.

S Valence Stabilizer #16e: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of sulfur and are contained in component 6-memberedheterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:octathiopyrans; octathiazines; octathiaphosphorins;octathiadiphosphorins; octaoxathiins; and octadithiins.

S Valence Stabilizer #16f: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all nine binding sites arecomposed of sulfur and are contained in component 6-memberedheterocyclic rings (S—S Tridentates, S—S Tetradentates, or S—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:nonathiopyrans; nonathiazines; nonathiaphosphorins;nonathiadiphosphorins; nonaoxathiins; and nonadithiins.

S Valence Stabilizer #16g: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof sulfur and are contained in component 6-membered heterocyclic rings(S—S Tridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: decathiopyrans; decathiazines;decathiaphosphorins; decathiadiphosphorins; decaoxathiins; anddecadithiins.

S Valence Stabilizer #17a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of sulfur and are contained in a combination of 6-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithiatetrathiopyrans; tetrathiatetrathiopyrans; dithiatetrathiazines;tetrathiatetrathiazines; dithiatetrathiaphosphorins;tetrathiatetrathiaphosphorins; dithiatetraoxathiins;tetrathiatetraoxathiins; dithiatetradithiins; andtetrathiatetradithiins.

S Valence Stabilizer #17b: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all five binding sites arecomposed of sulfur and are contained in a combination of 6-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates or S—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithiapentathiopyrans; tetrathiapentathiopyrans;dithiapentathiazines; tetrathiapentathiazines;dithiapentathiaphosphorins; tetrathiapentathiaphosphorins;dithiapentaoxathiins; tetrathiapentaoxathiins; dithiapentadithiins; andtetrathiapentadithiins.

S Valence Stabilizer #17c: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof sulfur and are contained in a combination of 6-membered heterocyclicrings and thiol, thioether, or thioketo groups (S—S Tridentates, S—STetradentates, or S—S Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dithiahexathiopyrans; trithiahexathiopyrans;dithiahexathiazines; trithiahexathiazines; dithiahexathiaphosphorins;trithiahexathiaphosphorins; dithiahexaoxathiins; trithiahexaoxathiins;dithiahexadithiins; and trithiahexadithiins.

S Valence Stabilizer #17d: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all seven binding sites arecomposed of sulfur and are contained in a combination of 6-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiaheptathiopyrans;tetrathiaheptathiopyrans; dithiaheptathiazines; tetrathiaheptathiazines;dithiaheptathiaphosphorins; tetrathiaheptathiaphosphorins;dithiaheptaoxathiins; tetrathiaheptaoxathiins; dithiaheptadithiins; andtetrathiaheptadithiins.

S Valence Stabilizer #17e: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of sulfur and are contained in a combination of 6-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiaoctathiopyrans;tetrathiaoctathiopyrans; dithiaoctathiazines; tetrathiaoctathiazines;dithiaoctathiaphosphorins; tetrathiaoctathiaphosphorins;dithiaoctaoxathiins; tetrathiaoctaoxathiins; dithiaoctadithiins; andtetrathiaoctadithiins.

S Valence Stabilizer #17f: Examples of nine-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all nine binding sites arecomposed of sulfur and are contained in a combination of 6-memberedheterocyclic rings and thiol, thioether, or thioketo groups (S—STridentates, S—S Tetradentates, or S—S Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trithianonathiopyrans;hexathianonathiopyrans; trithianonathiazines; hexathianonathiazines;trithianonathiaphosphorins; hexathianonathiaphosphorins;trithianonaoxathiins; hexathianonaoxathiins; trithianonadithiins; andhexathianonadithiins.

S Valence Stabilizer #17g: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all ten binding sites are composedof sulfur and are contained in a combination of 6-membered heterocyclicrings and thiol, thioether, or thioketo groups (S—S Tridentates, S—STetradentates, or S—S Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dithiadecathiopyrans; pentathiadecathiopyrans;dithiadecathiazines; pentathiadecathiazines; dithiadecathiaphosphorins;pentathiadecathiaphosphorins; dithiadecaoxathiins;pentathiadecaoxathiins; dithiadecadithiins; and pentathiadecadithiins.

S Valence Stabilizer #18: Examples of dithiobiurets(dithioimidodicarbonic diamides), dithioisobiurets, dithiobiureas,trithiotriurets, trithiotriureas, bis(dithiobiurets),bis(dithioisobiurets), bis(dithiobiureas), poly(dithiobiurets),poly(dithioisobiurets), and poly(dithiobiureas) (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithiobiuret, dithioisobiuret, dithiobiurea, trithiotriuret,trithiotriurea, nitrodithiobiuret, dinitrodithiobiuret,aminodithiobiuret, diaminodithiobiuret, oxydithiobiuret,dioxydithiobiuret, cyanodithiobiuret, methyldithiobiuret,ethyldithiobiuret, isopropyldithiobiuret, phenyldithiobiuret,benzyldithiobiuret, cyclohexyldithiobiuret, norbornyldithiobiuret,adamantyldithiobiuret, dimethyldithiobiuret, diethyldithiobiuret,diisopropyldithiobiuret, diphenyldithiobiuret, dibenzyldithiobiuret,dicyclohexyldithiobiuret, dinorbornyldithiobiuret, anddiadamantyldithiobiuret.

S Valence Stabilizer #19: Examples of thioacylthioureas,thioaroylthioureas, bis(thioacylthioureas), bis(thioaroylthioureas),poly(thioacylthioureas), and poly(thioaroylthioureas) (S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: thioformylthiourea, thioacetylthiourea, thiobenzoylthiourea,thiocyclohexoylthiourea, pentafluorothiobenzoylthiourea,N-methylthioacetylthiourea, N-phenylthiobenzoylthiourea, andN-cyclohexylthiocyclohexoylthiourea.

S Valence Stabilizer #20: Examples of dithioacyl disulfides,bis(dithioacyl disulfides), and poly(dithioacyl disulfides), (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithioacetyl disulfide; dithiopropanoyldisulfide; dithiobenzoyl disulfide; and dithiopentafluorobenzoyldisulfide.

S Valence Stabilizer #21: Examples of tetrathioperoxydicarbonicdiamides, bis(tetrathioperoxydicarbonic diamides), andpoly(tetrathioperoxydicarbonic diamides) (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: tetrathioperoxydicarbonic diamide; N-phenyltetrathioperoxydicarbonicdiamide; N-benzyltetrathioperoxydicarbonic diamide;N-cyclohexyltetrathioperoxydicarbonic diamide;N-norbornyltetrathioperoxydicarbonic diamide;N,N′-diphenyltetrathioperoxydicarbonic diamide;N,N′-dibenzyltetrathioperoxydicarbonic diamide;N,N′-dicyclohexyltetrathioperoxydicarbonic diamide; andN,N′-dinorbornyltetrathioperoxydicarbonic diamide.

S Valence Stabilizer #22: Examples of hexathio-, pentathio-, andtetrathioperoxydicarbonic acids, bis(hexathio-, pentathio-, andtetrathioperoxydicarbonic acids), poly(hexathio-, pentathio-, andtetrathioperoxydicarbonic acids), and derivatives thereof (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: hexathioperoxydicarbonic acid,pentathioperoxydicarbonic acid, tetrathioperoxydicarbonic acid,S-phenylhexathioperoxydicarbonic acid; S-benzylhexathioperoxydicarbonicacid; S-cyclohexylhexathioperoxydicarbonic acid;S-norbornylhexathioperoxydicarbonic acid;S,S′-diphenylhexathioperoxydicarbonic acid;S,S′-dibenzylhexathioperoxydicarbonic acid;S,S′-dicyclohexylhexathioperoxydicarbonic acid; andS,S′-dinorbornylhexathioperoxydicarbonic acid.

S Valence Stabilizer #23: Examples of dithioperoxydiphosphoramides,bis(dithioperoxydiphosphoramides), andpoly(dithioperoxydiphosphoramides) (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithioperoxydiphosphoramide, N-methyldithioperoxydiphosphoramide,N-isopropyldithioperoxydiphosphoramide,N-tert-butyldithioperoxydiphosphoramide,N-phenyldithioperoxydiphosphoramide,N-pentafluorophenyldithioperoxydiphosphoramide,N-benzyldithioperoxydiphosphoramide,N-cyclohexyldithioperoxydiphosphoramide,N-norbornyldithioperoxydiphosphoramide,N,N′″-dimethyldithioperoxydiphosphoramide,N,N′″-diisopropyldithioperoxydiphosphoramide,N,N′″-di-tert-butyldithioperoxydiphosphoramide,N,N′″-diphenyldithioperoxydiphosphoramide,N,N′″-di-pentafluorophenyldithioperoxydiphosphoramide,N,N′″-diphenyldithioperoxydiphosphoramide,N,N′″-dicyclohexyldithioperoxydiphosphoramide, andN,N′″-dinorbornyldithioperoxydiphosphoramide.

S Valence Stabilizer #24: Examples of dithioperoxydiphosphoric acids,bis(dithioperoxydiphosphoric acids), poly(dithioperoxydiphosphoricacids), and derivatives thereof (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithioperoxydiphosphoric acid, methyldithioperoxydiphosphoric acid,isopropyldithioperoxydiphosphoric acid,tert-butyldithioperoxydiphosphoric acid, phenyldithioperoxydiphosphoricacid, pentafluorophenyldithioperoxydiphosphoric acid,benzyldithioperoxydiphosphoric acid, cyclohexyldithioperoxydiphosphoricacid, norbornyldithioperoxydiphosphoric acid,dimethyldithioperoxydiphosphoric acid,diisopropyldithioperoxydiphosphoric acid,di-tert-butyldithioperoxydiphosphoric acid,diphenyldithioperoxydiphosphoric acid,di-pentafluorophenyldithioperoxydiphosphoric acid,dibenzyldithioperoxydiphosphoric acid,dicyclohexyldithioperoxydiphosphoric acid, anddinorbornyldithioperoxydiphosphoric acid.

S Valence Stabilizer #25: Examples of dithioimidodiphosphonic acids,dithiohydrazidodiphosphonic acids, bis(dithioimidodiphosphonic acids),bis(dithiohydrazidodiphosphonic acids), poly(dithioimidodiphosphonicacids), poly(dithiohydrazidodiphosphonic acids), and derivatives thereof(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithioimidodiphosphonic acid,methyldithioimidodiphosphonic acid, isopropyldithioimidodiphosphonicacid, tert-butyldithioimidodiphosphonic acid,phenyldithioimidodiphosphonic acid,pentafluorophenyldithioimidodiphosphonic acid,benzyldithioimidodiphosphonic acid, cyclohexyldithioimidodiphosphonicacid, norbornyldithioimidodiphosphonic acid,dimethyldithioimidodiphosphonic acid,diisopropyldiothioimidodiphosphonic acid,di-tert-butyldithioimidodiphosphonic acid,diphenyldithioimidodiphosphonic acid,di-pentafluorophenyldithioimidodiphosphonic acid,dibenzyldithioimidodiphosphonic acid,dicyclohexyldithioimidodiphosphonic acid, anddinorbornyldithioimidodiphosphonic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S Valence Stabilizer #26: Examples of dithioimidodiphosphonamides,dithiohydrazidodiphosphonamides, bis(dithioimidodiphosphonamides),bis(dithiohydrazidodiphosphonamides), poly(dithioimidodiphosphonamides),and poly(dithiohydrazidodiphosphonamides) (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: dithioimidodiphosphonamide, N-methyldithioimidodiphosphonamide,N-isopropyldithioimidodiphosphonamide,N-tert-butyldithioimidodiphosphonamide,N-phenyldithioimidodiphosphonamide,N-pentafluorophenyldithioimidodiphosphonamide,N-benzyldithioimidodiphosphonamide,N-cyclohexyldithioimidodiphosphonamide,N-norbornyldithioimidodiphosphonamide,N,N′″-dimethyldithioimidodiphosphonamide,N,N′″-diisopropyldithioimidodiphosphonamide,N,N′″-di-tert-butyldithioimidodiphosphonamide,N,N′″-diphenyldithioimidodiphosphonamide,N,N′″-di-pentafluorophenyldithioimidodiphosphonamide,N,N′″-dibenzyldithioimidodiphosphonamide,N,N′″-dicyclohexyldithioimidodiphosphonamide, andN,N′″-dinorbornyldithioimidodiphosphonamide. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S Valence Stabilizer #27: Examples of dithiodiphosphonamides,bis(dithiodiphosphonamides), and poly(dithiodiphosphonamides) (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiodiphosphonamide,N-methyldithiodiphosphonamide, N-isopropyldithiodiphosphonamide,N-tert-butyldithiodiphosphonamide, N-phenyldithiodiphosphonamide,N-pentafluorophenyldithiodiphosphonamide, N-benzyldithiodiphosphonamide,N-cyclohexyldithiodiphosphonamide, N-norbornyldithiodiphosphonamide,N,N′″-dimethyldithiodiphosphonamide,N,N′″-diisopropyldithiodiphosphonamide,N,N′″-di-tert-butyldithiodiphosphonamide,N,N′″-diphenyldithiodiphosphonamide,N,N′″-di-pentafluorophenyldithiodiphosphonamide,N,N′″-dibenzyldithiodiphosphonamide,N,N′″-dicyclohexyldithiodiphosphonamide, andN,N′″-dinorbornyldithiodiphosphonamide. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S Valence Stabilizer #28: Examples of dithiodiphosphonic acids,bis(dithiodiphosphonic acids), poly(dithiodiphosphonic acids), andderivatives thereof (S—S Bidentates, S—S Tridentates, S—S Tetradentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: dithiodiphosphonic acid,methyldithiodiphosphonic acid, isopropyldithiodiphosphonic acid,tert-butyldithiodiphosphonic acid, phenyldithiodiphosphonic acid,pentafluorophenyldithiodiphosphonic acid, benzyldithiodiphosphonic acid,cyclohexyldithiodiphosphonic acid, norbornyldithiodiphosphonic acid,dimethyldithiodiphosphonic acid, diisopropyldiothiodiphosphonic acid,di-tert-butyldithiodiphosphonic acid, diphenyldithiodiphosphonic acid,di-pentafluorophenyldithiodiphosphonic acid, dibenzyldithiodiphosphonicacid, dicyclohexyldithiodiphosphonic acid, anddinorbornyldithiodiphosphonic acid. [Note: the phosphite (P⁺³) valenceof the phosphorus atom makes stabilizization of high valence metal ionsmuch more difficult, though still possible.]

S Valence Stabilizer #29: Examples of dithioperoxydiphosphonamides,bis(dithioperoxydiphosphonamides), andpoly(dithioperoxydiphosphonamides) (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithioperoxydiphosphonamide, N-methyldithioperoxydiphosphonamide,N-isopropyldithioperoxydiphosphonamide,N-tert-butyldithioperoxydiphosphonamide,N-phenyldithioperoxydiphosphonamide,N-pentafluorophenyldithioperoxydiphosphonamide,N-benzyldithioperoxydiphosphonamide,N-cyclohexyldithioperoxydiphosphonamide,N-norbornyldithioperoxydiphosphonamide,N,N′″-dimethyldithioperoxydiphosphonamide,N,N′″-diisopropyldithioperoxydiphosphonamide,N,N′″-di-tert-butyldithioperoxydiphosphonamide,N,N′″-diphenyldithioperoxydiphosphonamide,N,N′″-di-pentafluorophenyldithioperoxydiphosphonamide,N,N′″-dibenzyldithioperoxydiphosphonamide,N,N′″-dicyclohexyldithioperoxydiphosphonamide, andN,N′″-dinorbornyldithioperoxydiphosphonamide. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S Valence Stabilizer #30: Examples of dithioperoxydiphosphonic acids,bis(dithioperoxydiphosphonic acids), poly(dithioperoxydiphosphonicacids), and derivatives thereof (S—S Bidentates, S—S Tridentates, S—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithioperoxydiphosphonic acid, methyldithioperoxydiphosphonic acid,isopropyldithioperoxydiphosphonic acid,tert-butyldithioperoxydiphosphonic acid, phenyldithioperoxydiphosphonicacid, pentafluorophenyldithioperoxydiphosphonic acid,benzyldithioperoxydiphosphonic acid, cyclohexyldithioperoxydiphosphonicacid, norbornyldithioperoxydiphosphonic acid,dimethyldithioperoxydiphosphonic acid,diisopropyldithioperoxydiphosphonic acid,di-tert-butyldithioperoxydiphosphonic acid,diphenyldithioperoxydiphosphonic acid,di-pentafluorophenyldithioperoxydiphosphonic acid,dibenzyldithioperoxydiphosphonic acid,dicyclohexyldithioperoxydiphosphonic acid, anddinorbornyldithioperoxydiphosphonic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S Valence Stabilizer #31: Examples of dithiophosphonic acids(phosphonodithioic acids), bis(dithiophosphonic acids),poly(dithiophosphonic acids), and derivatives thereof (S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dithiophosphonic acid, O-phenyldithiophosphonic acid,O-benzyldithiophosphonic acid, O-cyclohexyldithiophosphonic acid,O-norbornyldithiophosphonic acid, O,P-diphenyldithiophosphonic acid,O,P-dibenzyldithiophosphonic acid, O,P-dicyclohexyldithiophosphonicacid, and O,P-dinorbornyldithiophosphonic acid. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.]

S Valence Stabilizer #32: Examples of trithiophosphonic acids(phosphonotrithioic acids), bis(trithiophosphonic acids),poly(trithiophosphonic acids), and derivatives thereof (S—S Bidentates,S—S Tridentates, S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: trithiophosphonic acid, S-phenyltrithiophosphonic acid,S-benzyltrithiophosphonic acid, S-cyclohexyltrithiophosphonic acid,S-norbornyltrithiophosphonic acid, S,P-diphenyltrithiophosphonic acid,S,P-dibenzyltrithiophosphonic acid, S,P-dicyclohexyltrithiophosphonicacid, and S,P-dinorbornyltrithiophosphonic acid. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.]

S Valence Stabilizer #33: Examples of phosphono(dithioperoxo)thioicacids, bis[phosphono(dithioperoxo)thioic acids],poly[phosphono(dithioperoxo)thioic acids], and derivatives thereof (S—SBidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphono(dithioperoxo)thioic acid,O-phenylphosphono(dithioperoxo)thioic acid,O-benzylphosphono(dithioperoxo)thioic acid,O-cyclohexylphosphono(dithioperoxo)thioic acid,O-norbornylphosphono(dithioperoxo)thioic acid,O,P-diphenylphosphono(dithioperoxo)thioic acid,O,P-dibenzylphosphono(dithioperoxo)thioic acid,O,P-dicyclohexylphosphono(dithioperoxo)thioic acid, andO,P-dinorbornylphosphono(dithioperoxo)thioic acid. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.]

S Valence Stabilizer #34: Examples of phosphono(dithioperoxo)dithioicacids, bis[phosphono(dithioperoxo)dithioic acids],poly[phosphono(dithioperoxo)dithioic acids], and derivatives thereof(S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphono(dithioperoxo)dithioic acid,S-phenylphosphono(dithioperoxo)dithioic acid,S-benzylphosphono(dithioperoxo)dithioic acid,S-cyclohexylphosphono(dithioperoxo)dithioic acid,S-norbornylphosphono(dithioperoxo)dithioic acid,S,P-diphenylphosphono(dithioperoxo)dithioic acid,S,P-dibenzylphosphono(dithioperoxo)dithioic acid,S,P-dicyclohexylphosphono(dithioperoxo)dithioic acid, andS,P-dinorbornylphosphono(dithioperoxo)dithioic acid. [Note: thephosphite (P⁺³) valence of the phosphorus atom makes stabilizization ofhigh valence metal ions much more difficult, though still possible.]

S Valence Stabilizer #35: Examples of S-(alkylthio)thiocarboxylic acids,S-(arylthio)thiocarboxylic acids, and S,S-thiobisthiocarboxylic Acids(S—S Bidentates and S—S Tridentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: (methylthio)thioacetic acid; (methylthio)thiobenzoic acid;(methylthio)thionicotinic acid; (methylthio)thionapthoic acid;(phenylthio)thioacetic acid; (phenylthio)thiobenzoic acid;(phenylthio)thionaphthoic acid; (norbornylthio)thioacetic acid;(norbornylthio)thiobenzoic acid; (norbornylthio)thionapthoic acid;thiobisthioacetic acid; thiobisthiobenzoic acid; and thiobisthionapthoicacid.

S Valence Stabilizer #36: Examples of S-(alkyldisulfido)thiocarboxylicacids, S-(aryldisulfido)thiocarboxylic acids, andS,S′-disulfidobisthiocarboxylic acids (S—S Bidentates and S—STridentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to:(methyldisulfido)thioacetic acid; (methyldisulfido)thiobenzoic acid;(methyldisulfido)thionicotinic acid; (methyldisulfido)thionapthoic acid;(phenyldisulfido)thioacetic acid; (phenyldisulfido)thiobenzoic acid;(phenyldisulfido)thionaphthoic acid; (norbornyldisulfido)thioaceticacid; (norbornyldisulfido)thiobenzoic acid;(norbornyldisulfido)thionapthoic acid; S,S′-disulfidobisthioacetic acid;S,S′-disulfidobisthiobenzoic acid; and S,S′-disulfidobisthionapthoicacid.

S Valence Stabilizer #37: Examples of 1,2-dithiolates,bis(1,2-dithiolates), and poly(1,2-dithiolates) (S—S Bidentates, S—STridentates, S—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 2,3-butanedithiol; 1,2-diphenyl-1,2-ethanedithiol;1,2-di(pentafluorophenyl)-1,2-ethanedithio;1,2-dicyclohexyl-1,2-ethanedithiol; 1,2-dinorbornyl-1,2-ethanedithiol;2,3-dimercaptopropanol; 2,3-dimercaptosuccinic acid;poly[bis(arylthio)acetylene]s; and poly[bis(alkylylthio)acetylene]s.

S Valence Stabilizer #38: Examples of rhodanines and bis(rhodanines)(S—S Bidentates and S—S Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 3-methylrhodanine; 3-ethylrhodanine; 3-isopropylrhodanine;3-phenylrhodanine; 3-benzylrhodanine; 3-cyclohexylrhodanine;3-norbornylrhodanine; 5-methylrhodanine; 5-ethylrhodanine;5-isopropylrhodanine; 5-phenylrhodanine; 5-benzylrhodanine;5-cyclohexylrhodanine; 5-norbornylrhodanine; 3,3′-ethylenebisrhodanine;3,3′-propylenerhodanine; 3,3′-butylenerhodanine;5,5′-ethylenebisrhodanine; 5,5′-propylenerhodanine; and5,5′-butylenerhodanine. [Note: rhodanines and bis(rhodanines) tend tostabilize lower oxidation states in metal ions.]

S Valence Stabilizer #39: Examples of dithiocarbimates,bis(dithiocarbimates), and poly(dithiocarbimates) (S—S Bidentates, S—STridentates, and S—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: methyldithiocarbimate; trifluoromethyldithiocarbimate;ethyldithiocarbimate; propyldithiocarbimate; isopropyldithiocarbimate;butyldithiocarbimate; tertbutyldithiocarbimate; cyanodithiocarbimate(CDC); cyanamidodithiocarbimate; azidodithiocarbimate;phenyldithiocarbimate; pentafluorophenyldithiocarbimate;benzyldithiocarbimate; naphthyldithiocarbimate;cyclohexyldithiocarbimate; norbornyldithiocarbimate; andadamantyldithiocarbimate. [Note: carbimates tend to stabilize loweroxidation states in metal ions.]

S Valence Stabilizer #40: Examples of thioxanthates, bis(thioxanthates),and poly(thioxanthates) (S—S Bidentates and S—S Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: methyl thioxanthate (MeSxan); ethylthioxanthate (EtSxan); isopropyl thioxanthate (iPrSxan); trifluoromethylthioxanthate (CF₃Sxan); cyanothioxanthate; cyanamidothioxanthate; phenylthioxanthate (PhSxan); benzyl thioxanthate (BzSxan); pentafluorophenylthioxanthate; cyclohexyl thioxanthate (cHxSxan); and norbornylthioxanthate. [Note: thioxanthates tend to stabilize lower oxidationstates in metal ions.]

S Valence Stabilizer #41: Examples of xanthates, bis(xanthates), andpoly(xanthates) (S—S Bidentates and S—S Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: methyl xanthate (Mexan); ethyl xanthate(Etxan); isopropyl xanthate (iPrxan); trifluoromethyl xanthate (CF₃xan);cyanoxanthate; cyanamidoxanthate; phenyl xanthate (Phxan); benzylxanthate (Bzxan); pentafluorophenyl xanthate; cyclohexyl xanthate(cHxxan); and norbornyl xanthate. [Note: xanthates tend to stabilizelower oxidation states in metal ions.]

S Valence Stabilizer #42: Examples of phosphinodithioformates (S—SBidentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to:trimethylphosphinodithioformate; triethylphosphinodithioformate;triphenylphosphinodithioformate; tricyclohexylphosphinodithioformate;dimethylphosphinodithioformate; diethylphosphinodithioformate;diphenylphosphinodithioformate; and dicyclohexylphosphinodithioformate.

S Valence Stabilizer #43: Examples of alkyl- and aryl-dithioborates,trithioborates, perthioborates, bis(dithioborates), bis(trithioborates),and bis(perthioborates) (S—S Bidentates and S—S Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: S,O-diethyl dithioborate;S,O-diisopropyl dithioborate; S,O-diphenyl dithioborate; S,O-dibenzyldithioborate; S,O-dicyclohexyl dithioborate; S,O-dinorbornyldithioborate; diethyl trithioborate; diisopropyl trithioborate; diphenyltrithioborate; dibenzyl trithioborate; dicyclohexyl trithioborate; anddinorbornyl trithioborate.

S Valence Stabilizer #44: Examples of alkyl- and aryl-dithioboronatesand bis(dithioboronates) (S—S Bidentates and S—S Tetradentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: diethyl dithioboronate;diisopropyl dithioboronate; diphenyl dithioboronate; dibenzyldithioboronate; dicyclohexyl dithioboronate; and dinorbornyldithioboronate. [Note: boronates tend to stabilize lower oxidationstates in metal ions.]

S Valence Stabilizer #45: Examples of trithioarsonic acids(arsonotrithioic acids), dithioarsonic acids (arsonodithioic acids),tetrathioarsonic acids (arsonotetrathioic acids), and derivativesthereof (S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trithioarsonic acid,O-phenyltrithioarsonic acid, O-benzyltrithioarsonic acid,O-cyclohexyltrithioarsonic acid, O-norbornyltrithioarsonic acid,O,S-diphenyltrithioarsonic acid, O,S-dibenzyltrithioarsonic acid,O,S-dicyclohexyltrithioarsonic acid, O,S-dinorbornyltrithioarsonic acid;dithioarsonic acid, O-phenyldithioarsonic acid, O-benzyldithioarsonicacid, O-cyclohexyldithioarsonic acid, O-norbornyldithioarsonic acid,O,O-diphenyldithioarsonic acid, O,O-dibenzyldithioarsonic acid,O,O-dicyclohexyldithioarsonic acid, and O,O-dinorbornyldithioarsonicacid.

S Valence Stabilizer #46: Examples of trithioantimonic acids(stibonotrithioic acids), dithioantimonic acids (stibonodithioic acids),tetrathioantimonic acids (stibonotetrathioic acids), and derivativesthereof (S—S Bidentates, S—S Tridentates, S—S Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trimethyltrithioantimonate;triethyltrithioantimonate; and triphenyltrithioantimonate.

S Valence Stabilizer #47: Examples of phosphine P-sulfides andamino-substituted phosphine sulfides (S Monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trimethylphosphine sulfide (TMPS);triethylphosphine sulfide (TEPS); triphenylphosphine sulfide (TPhPS);tribenzylphosphine sulfide (TBzPS); tricyclohexylphosphine sulfide(TcHxPS); and trinorbornylphosphine sulfide for phosphine P-sulfides;and tris(dimethylamino)phosphine sulfide; trimorpholinophosphinesulfide; tripiperidinophosphine sulfide; tripyrrolidinophosphinesulfide; and tri(cyclohexylamino)phosphine sulfide for amino-substitutedphosphine sulfides.

S Valence Stabilizer #48: Examples of arsine As-sulfides andamino-substituted arsine sulfides (S Monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trimethylarsine sulfide; triethylarsinesulfide; triphenylarsine sulfide; tribenzylarsine sulfide;tricyclohexylarsine sulfide; and trinorbornylarsine sulfide for arsineAs-sulfides; and tris(dimethylamino)arsine sulfide; trimorpholinoarsinesulfide; tripiperidinoarsine sulfide; tripyrrolidinoarsine sulfide; andtri(cyclohexylamino)arsine sulfide for amino-substituted arsinesulfides.

S Valence Stabilizer #49: Examples of thiolates that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: thiophenol; naphthalenethiol;1-dodecanethion; hexadecyl mercaptan; benzenethiol (bt);polybenzenethiols; and polythioarylenes.

S Valence Stabilizer #50: Examples of sulfide that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: sulfides (—S²⁻); disulfides (—S₂ ²⁻); and polysulfides(—S_(x) ²⁻).

P Valence Stabilizer #1: Examples of monophosphines (P monodentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: phosphine, phenylphosphine,diphenylphosphine, triphenylphosphine, tricyclohexylphosphine,phenyldimethylphosphine, phenyldiethylphosphine,methyldiphenylphosphine, ethyldiphenylphosphine, phosphirane,phosphetane, phospholane, phosphorinane, benzophospholane,benzophosphorinane, dibenzophospholane, dibenzophosphorinane,naphthophospholane, naphthophosphorinane, phosphinonorbornane, andphosphinoadamantane.

P Valence Stabilizer #2: Examples of diphosphines (P monodentates or P—Pbidentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to: diphospholane,benzodiphospholane, naphthodiphospholane, diphosphorinane,benzodiphosphorinane, dibenzodiphosphorinane, naphthodiphosphorinane,bis(diphenylphosphino)methane, bis(diphenylphosphino)ethane,bis(diphenylphosphino)propane, bis(diphenylphosphino)butane,bis(diphenylphosphino)pentane, 1,2-bis(diphenylphosphino)ethylene, ando-phenylenebis(diphenylphosphine). [Note: the aryl derivatives areair-stable, whereas the alkyl derivatives are air-sensitive andtherefore unsuitable for these applications.]

P Valence Stabilizer #3: Examples of triphosphines (P monodentates, P—Pbidentates, or P—P tridentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: triphosphorinane,P,P′-tetraphenyl-2-methyl-2-(P-diphenyl)phosphinomethyl-1,3-propanediphosphine;P,P-[2-(P-diphenyl)phosphinoethyl]diethyl-P-phenylphosphine;P,P-[2-(P-diphenyl)phosphino]diphenyl-P-phenylphosphine; andhexahydro-2,4,6-trimethyl-1,3,5-triphosphazine. [Note: the arylderivatives are air-stable, whereas the alkyl derivatives areair-sensitive and therefore unsuitable for these applications.]

P Valence Stabilizer #4: Examples of tetraphosphines (P monodentates,P—P bidentates, P—P tridentates, and P—P tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to:P,P′-tetraphenyl-2,2-[(P-diphenyl)phosphinomethyl]-1,3-propanediphosphine;tri[o-(P-diphenyl)phosphinophenyl]phosphine; and1,1,4,7,10,10-hexaphenyl-1,4,7,10-tetraphosphadecane. [Note: the arylderivatives are air-stable, whereas the alkyl derivatives areair-sensitive and therefore unsuitable for these applications.]

P Valence Stabilizer #5: Examples of pentaphosphines (P monodentates,P—P bidentates, P—P tridentates, and P—P tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to:4-[2-(P-diphenyl)phosphinoethyl]-1,1,7,10,10-pentaphenyl-1,4,7,10-tetraphosphadecane.[Note: the aryl derivatives are air-stable, whereas the alkylderivatives are air-sensitive and therefore unsuitable for theseapplications.]

P Valence Stabilizer #6: Examples of hexaphosphines (P—P bidentates, P—Ptridentates, P—P tetradentates, and P—P hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to:1,1,10,10-tetraphenyl-4,7-[2-(P,P-diphenyl)phosphinoethyl]-1,4,7,10-tetraphosphadecane.[Note: the aryl derivatives are air-stable, whereas the alkylderivatives are air-sensitive and therefore unsuitable for theseapplications.]

P Valence Stabilizer #7a: Examples of 5-membered heterocyclic ringscontaining one phosphorus atom (P monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 1-phospholene, 2-phospholene,3-phospholene, phosphole, oxaphosphole, thiaphosphole, benzophospholene,benzophosphole, benzoxaphosphole, benzothiaphosphole,dibenzophospholene, dibenzophosphole, naphthophospholene,naphthophosphole, naphthoxaphosphole, naphthothiaphosphole.

P Valence Stabilizer #7b: Examples of 5-membered heterocyclic ringscontaining two phosphorus atoms (P monodentates or P—P bidentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: diphospholene, diphosphole,oxadiphospholene, thiadiphospholene, benzodiphospholene,benzodiphosphole, naphthodiphospholene, and naphthodiphosphole.

P Valence Stabilizer #7c: Examples of 5-membered heterocyclic ringscontaining three phosphorus atoms (P monodentates or P—P bidentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: triphosphole.

P Valence Stabilizer #8a: Examples of 6-membered heterocyclic ringscontaining one phosphorus atom (P monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphorin, oxaphosphorin,thiaphosphorin, benzophosphorin, benzoxaphosphorin, benzothiaphosphorin,acridophosphine, phosphanthridine, dibenzoxaphosphorin,dibenzothiaphosphorin, naphthophosphorin, naphthoxaphosphorin, andnaphthothiaphosphorin. P Valence Stabilizer #8b: Examples of 6-memberedheterocyclic rings containing two phosphorus atoms (P monodentates orP—P bidentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:o-diphosphorin, m-diphosphorin, p-diphosphorin, oxadiphosphorin,thiadiphosphorin, benzodiphosphorin, benzoxadiphosphorin,benzothiadiphosphorin, dibenzodiphosphorin, dibenzoxadiphosphorin,dibenzothiadiphosphorin, naphthodiphosphorin, naphthoxadiphosphorin, andnaphthothiadiphosphorin.

P Valence Stabilizer #8c: Examples of 6-membered heterocyclic ringscontaining three phosphorus atoms (P monodentates or P—P bidentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 1,3,5-triphosphorin,1,2,3-triphosphorin, benzo-1,2,3-triphosphorin, andnaphtho-1,2,3-triphosphorin.

P Valence Stabilizer #9a: Examples of 5-membered heterocyclic ringscontaining one phosphorus atom and having at least one additionalphosphorus atom binding site not contained in a ring (P Monodentates,P—P Bidentates, P—P Tridentates, P—P Tetradentates, or P—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2-(P-phenylphosphino)-1-phospholene;2,5-(P-phenylphosphino)-1-phospholene;2-(P-phenylphosphino)-3-phospholene;2,5-(P-phenylphosphino)-3-phospholene; 2-(P-phenylphosphino)phosphole;2,5-(P-phenylphosphino)phosphole; 2-(P-phenylphosphino)benzophosphole;7-(P-phenylphosphino)benzophosphole; and1,8-(P-phenylphosphino)dibenzophosphole.

P Valence Stabilizer #9b: Examples of 5-membered heterocyclic ringscontaining two phosphorus atoms and having at least one additionalphosphorus atom binding site not contained in a ring (P Monodentates,P—P Bidentates, P—P Tridentates, P—P Tetradentates, or P—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2-(P-phenylphosphino)-1,3-diphospholene;2,5-(P-phenylphosphino)-1,3-diphospholene;2-(P-phenylphosphino)-1,3-diphosphole;2,5-(P-phenylphosphino)-1,3-diphosphole;2-(P-phenylphosphino)benzodiphosphole; and7-(P-phenylphosphino)benzodiphosphole.

P Valence Stabilizer #9c: Examples of 5-membered heterocyclic ringscontaining three phosphorus atoms and having at least one additionalphosphorus atom binding site not contained in a ring (P Monodentates,P—P Bidentates, P—P Tridentates, P—P Tetradentates, or P—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2-(P-phenylphosphino)-1,3,4-triphosphole; and2,5-(P-phenylphosphino)-1,3,4-triphosphole.

P Valence Stabilizer #10a: Examples of 6-membered heterocyclic ringscontaining one phosphorus atom and having at least one additionalphosphorus atom binding site not contained in a ring (P Monodentates,P—P Bidentates, P—P Tridentates, P—P Tetradentates, or P—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2-(P-phenylphosphino)phosphorin; 2,5-(P-phenylphosphino)phosphorin;2-(P-phenylphosphino)benzophosphorin;7-(P-phenylphosphino)benzophosphorin; and1,9-(P-phenylphosphino)acridophosphine.

P Valence Stabilizer #10b: Examples of 6-membered heterocyclic ringscontaining two phosphorus atoms and having at least one additionalphosphorus atom binding site not contained in a ring (P Monodentates,P—P Bidentates, P—P Tridentates, P—P Tetradentates, or P—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2-(P-phenylphosphino)-4-diphosphorin;2,6-(P-phenylphosphino)-4-diphosphorin;2,3,5,6-(P-phenylphosphino)-4-diphosphorin;2-(P-phenylphosphino)benzo-1,4-diphosphorin;2,3-(P-phenylphosphino)benzo-1,4-diphosphorin;2,8-(P-phenylphosphino)benzo-1,4-diphosphorin;2,3,5,8-(P-phenylphosphino)benzo-1,4-diphosphorin;1,9-(P-phenylphosphino)dibenzodiphosphorin; and1,4,6,9-(P-phenylphosphino)dibenzodiphosphorin.

P Valence Stabilizer #10c: Examples of 6-membered heterocyclic ringscontaining three phosphorus atoms and having at least one additionalphosphorus atom binding site not contained in a ring (P Monodentates,P—P Bidentates, P—P Tridentates, P—P Tetradentates, or P—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2-(P-phenylphosphino)-1,3,5-triphosphorin;2,6-(P-phenylphosphino)-1,3,5-triphosphorin;4-(P-phenylphosphino)1,2,3-triphosphorin; and8-(P-phenylphosphino)benzo-1,2,3-triphosphorin.

P Valence Stabilizer #11a: Examples of 5-membered heterocyclic ringscontaining one phosphorus atom and having at least one additionalphosphorus atom binding site contained in a ring (P Monodentates, P—PBidentates, P—P Tridentates, P—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-1-phospholene; 2,2′,2″-tri-1-phospholene; 2,2′-bi-3-phospholene; 2,2′,2″-tri-3-phospholene;2,2′-biphosphole; 2,2′,2″-triphosphole; and 2,2′-bibenzophosphole.

P Valence Stabilizer #11b: Examples of 5-membered heterocyclic ringscontaining two phosphorus atoms and having at least one additionalphosphorus atom binding site contained in a ring (P Monodentates, P—PBidentates, P—P Tridentates, P—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-1,3-diphospholene;2,2′-bi-1,3-diphosphole; and 2,2′-bibenzo-1,3-diphosphole.

P Valence Stabilizer #11c: Examples of 5-membered heterocyclic ringscontaining three phosphorus atoms and having at least one additionalphosphorus atom binding site contained in a ring (P Monodentates, P—PBidentates, P—P Tridentates, P—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-1,3,4-triphosphole; and2,2′,2″-tri-1,3,4-triphosphole.

P Valence Stabilizer #12a: Examples of 6-membered heterocyclic ringscontaining one phosphorus atom and having at least one additionalphosphorus atom binding site contained in a ring (P Monodentates, P—PBidentates, P—P Tridentates, P—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-biphosphorin;2,2′,2″-triphosphorin; 2,2′,2″,2′″-tetraphosphorin;2,2′-bibenzophosphorin; and 8,8′-bibenzophosphorin.

P Valence Stabilizer #12b: Examples of 6-membered heterocyclic ringscontaining two phosphorus atoms and having at least one additionalphosphorus atom binding site contained in a ring (P Monodentates, P—PBidentates, P—P Tridentates, P—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 3,3′-bi-1,2-diphosphorin;3,3′,3″-tri-1,2-diphosphorin; 2,2′-bi-1,4-diphosphorin;2,2′,2″-tri-1,4-diphosphorin; 3,3′-bibenzo-1,2-diphosphorin;8,8′-bibenzo-1,2-diphosphorin; 2,2′-bibenzo-1,4-diphosphorin; and8,8′-bibenzo-1,4-diphosphorin.

P Valence Stabilizer #12c: Examples of 6-membered heterocyclic ringscontaining three phosphorus atoms and having at least one additionalphosphorus atom binding site contained in a ring (P Monodentates, P—PBidentates, P—P Tridentates, P—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-1,3,5-triphosphorin;2,2′,2″-tri-1,3,5-triphosphorin; 4,4′-bi-1,2,3-triphosphorin;4,4′-bibenzo-1,2,3-triphosphorin; and 8,8′-bibenzo-1,2,3-triphosphorin.

P Valence Stabilizer #13a: Examples of two-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein both binding sites are composed ofphosphorus and are not contained in component heterocyclic rings (P—PBidentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to:P,P-diphenyldiphosphacyclobutane ([4]aneP₂);P,P-diphenyldiphosphacyclopentane ([5]aneP₂);P,P-diphenyldiphosphacyclohexane ([6]aneP₂);P,P-diphenyldiphosphacyclopentane ([7]aneP₂);P,P-diphenyldiphosphacyclooctane ([8]aneP₂);P,P-diphenyldiphosphacyclobutene ([4]eneP₂);P,P-diphenyldiphosphacyclopentene ([5]eneP₂);P,P-diphenyldiphosphacyclohexene ([6]eneP₂);P,P-diphenyldiphosphacycloheptene ([7]eneP₂); andP,P-diphenyldiphosphacyclooctene ([8]eneP₂).

P Valence Stabilizer #13b: Examples of three-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofphosphorus and are not contained in component heterocyclic rings (P—PTridentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to:P,P,P-triphenyltriphosphacyclohexane ([6]aneP₃);P,P,P-triphenyltriphosphacycloheptane ([7]aneP₃);P,P,P-triphenyltriphosphacyclooctane ([8]aneP₃);P,P,P-triphenyltriphosphacyclononane ([9]aneP₃);P,P,P-triphenyltriphosphacyclodecane ([10]aneP₃);P,P,P-triphenyltriphosphacycloundecane ([11]aneP₃);P,P,P-triphenyltriphosphacyclododecane ([12]aneP₃);P,P,P-triphenyltriphosphacyclohexatriene ([6]trieneP₃);P,P,P-triphenyltriphosphacycloheptatriene ([7]trieneP₃);P,P,P-triphenyltriphosphacyclooctatriene ([8]trieneP₃);P,P,P-triphenyltriphosphacyclononatriene ([9]trieneP₃);P,P,P-triphenyltriphosphacyclodecatriene ([10]trieneP₃);P,P,P-triphenyltriphosphacycloundecatriene ([11]trieneP₃); andP,P,P-triphenyltriphosphacyclododecatriene ([12]trieneP₃).

P Valence Stabilizer #13c: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofphosphorus and are not contained in component heterocyclic rings (P—PTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:P,P,P,P-tetraphenyltetraphosphacyclooctane ([8]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclononane ([9]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclodecane ([10]aneP₄);P,P,P,P-tetraphenyltetraphosphacycloundecane ([11]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclododecane ([12]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclotridecane ([13]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclotetradecane ([14]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclopentadecane ([15]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclohexadecane ([16]aneP₄);P,P,P,P-tetraphenyltetraphosphacycloheptadecane ([17]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclooctadecane ([18]aneP₄);P,P,P,P-tetraphenyltetraphosphacyclononadecane ([19]aneP₄); andP,P,P,P-tetraphenyltetraphosphacycloeicosane ([20]aneP₄).

P Valence Stabilizer #13d: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofphosphorus and are not contained in component heterocyclic rings (P—PTridentates, or P—P Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: P,P,P,P,P-pentaphenylpentaphosphacyclodecane ([10]aneP₅);P,P,P,P,P-pentaphenylpentaphosphacycloundecane ([11]aneP₅);P,P,P,P,P-pentaphenylpentaphosphacyclododecane ([12]aneP₅);P,P,P,P,P-pentaphenylpentaphosphacyclotridecane ([13]aneP₅);P,P,P,P,P-pentaphenylpentaphosphacyclotetradecane ([14]aneP₅); andP,P,P,P,P-pentaphenylpentaphosphacyclopentadecane ([15]aneP₅).

P Valence Stabilizer #13e: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofphosphorus and are not contained in component heterocyclic rings (P—P—PTridentates, P—P—P—P Tetradentates, or P—P—P—P—P—P Hexadentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to:P,P,P,P,P,P-hexaphenylhexaphosphacyclododecane ([12]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclotridecane ([13]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclotetradecane ([14]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclopentadecane ([15]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclohexadecane ([16]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacycloheptadecane ([17]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclooctadecane ([18]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclononadecane ([19]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacycloeicosane ([20]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacycloheneicosane ([21]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclodocosane ([22]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclotricosane ([23]aneP₆);P,P,P,P,P,P-hexaphenylhexaphosphacyclotetracosane ([24]aneP₆).

P Valence Stabilizer #13f: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofphosphorus and are not contained in component heterocyclic rings (P—PTridentates, P—P Tetradentates, or P—P Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to:P,P,P,P,P,P,P,P-octaphenyloctaphosphacyclohexadecane ([16]aneP₈);P,P,P,P,P,P,P,P-octaphenyloctaphosphacycloheptadecane ([17]aneP₈);P,P,P,P,P,P,P,P-octaphenyloctaphosphacyclooctadecane ([18]aneP₈);P,P,P,P,P,P,P,P-octaphenyloctaphosphacyclononadecane ([19]aneP₈);P,P,P,P,P,P,P,P-octaphenyloctaphosphacycloeicosane ([20]aneP8);P,P,P,P,P,P,P,P-octaphenyloctaphosphacycloheneicosane ([21]aneP₈);P,P,P,P,P,P,P,P-octaphenyloctaphosphacyclodocosane ([22]aneP₈);P,P,P,P,P,P,P,P-octaphenyloctaphosphacyclotricosane ([23]aneP₈); andP,P,P,P,P,P,P,P-octaphenyloctaphosphacyclotetracosane ([24]aneP₈).

P Valence Stabilizer #14a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of phosphorus and are contained in component 5-memberedheterocyclic rings (P—P Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tetraphospholenes; tetraphospholes; tetraoxaphospholes;tetradiphospholenes; tetradiphospholes; and tetraoxadiphospholes.

P Valence Stabilizer #14b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof phosphorus and are contained in component 5-membered heterocyclicrings (P—P Tetradentates and P—P Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: hexaphospholenes; hexaphospholes;hexaoxaphospholes; hexadiphospholenes; hexadiphospholes; andhexaoxadiphospholes.

P Valence Stabilizer #14c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of phosphorus and are contained in component 5-memberedheterocyclic rings (P—P Tridentates; P—P Tetradentates; or P—PHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:octaphospholenes; octaphospholes; octaoxaphospholes; octadiphospholenes;octadiphospholes; and octaoxadiphospholes.

P Valence Stabilizer #15a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of phosphorus and are contained in a combination of 5-memberedheterocyclic rings and phosphine groups (P—P Tridentates, P—PTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diphosphatetraphospholenes; tetraphosphatetraphospholenes;diphosphatetraphospholes; tetraphosphatetraphospholes;diphoshatetradiphospholes; and tetraphosphatetradiphospholes.

P Valence Stabilizer #15b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof phosphorus and are contained in a combination of 5-memberedheterocyclic rings and phosphine groups (P—P Tridentates, P—PTetradentates, and P—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diphosphahexaphospholenes; triaphosphahexaphospholenes;diphosphahexaphospholes; triphosphahexaphospholes;diphoshahexadiphospholes; and triphosphahexadiphospholes.

P Valence Stabilizer #15c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of phosphorus and are contained in a combination of 5-memberedheterocyclic rings and phosphine groups (P—P Tridentates, P—PTetradentates, and P—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diphosphaoctaphospholenes; tetraphosphaoctaphospholenes;diphosphaoctaphospholes; tetraphosphaoctaphospholes;diphoshaoctadiphospholes; and tetraphosphaoctadiphospholes.

P Valence Stabilizer #16a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of phosphorus and are contained in component 6-memberedheterocyclic rings (P—P Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: cyclotetraphosphorins; cyclotetraaoxaphosphorins;cyclotetradiphosphorins; and cyclotetraoxadiphosphorins.

P Valence Stabilizer #16b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof phosphorus and are contained in component 6-membered heterocyclicrings (P—P Tridentates, P—P Tetradentates, and P—P Hexadentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: cyclohexaphosphorins;cyclohexaoxaphosphorins; cyclohexadiphosphorins; andcyclohexaoxadiphosphorins.

P Valence Stabilizer #16c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of phosphorus and are contained in component 6-memberedheterocyclic rings (P—P Tridentates, P—P Tetradentates, and P—PHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:cyclooctaphosphorins; cyclooctaoxaphosphorins; cyclooctadiphosphorins;and cyclooctaoxadiphosphorins.

P Valence Stabilizer #17a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of phosphorus and are contained in a combination of 6-memberedheterocyclic rings and phosphine groups (P—P Tridentates, P—PTetradentates, or P—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diphosphacyclotetraphosphorins;tetraphosphacyclotetraphosphorins; diphosphacyclotetraoxaphosphorins;tetraphosphacyclotetraoxaphosphorins; diphosphacyclotetradiphosphorins;tetraphosphacyclotetradiphosphorins;diphosphacyclotetraoxadiphosphorins; andtetraphosphacyclotetraoxadiphosphorins.

P Valence Stabilizer #17b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof phosphorus and are contained in a combination of 6-memberedheterocyclic rings and phosphine groups (P—P Tridentates, P—PTetradentates, or P—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diphosphacyclohexaphosphorins;triphosphacyclohexaphosphorins; diphosphacyclohexaoxaphosphorins;triphosphacyclohexaoxaphosphorins; diphosphacyclohexadiphosphorins;triphosphacyclohexadiphosphorins; diphosphacyclohexaoxadiphosphorins;and triphosphacyclohexaoxadiphosphorins.

P Valence Stabilizer #17c: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all eight binding sites arecomposed of phosphorus and are contained in a combination of 6-memberedheterocyclic rings and phosphine groups (P—P Tridentates, P—PTetradentates, or P—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diphosphacyclooctaphosphorins;tetraphosphacyclooctaphosphorins; diphosphacyclooctaoxaphosphorins;tetraphosphacyclooctaoxaphosphorins; diphosphacyclooctadiphosphorins;tetraphosphacyclooctadiphosphorins; diphosphacyclooctaoxadiphosphorins;and tetraphosphacyclooctaoxadiphosphorins.

O Valence Stabilizer #1: Examples of dithioperoxydicarbonic acids,bis(dithioperoxydicarbonic acids), poly(dithioperoxydicarbonic acids),and derivatives thereof (O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:dithioperoxydicarbonic acid, O-phenyldithioperoxydicarbonic acid;O-benzyldithioperoxydicarbonic acid; O-cyclohexyldithioperoxydicarbonicacid; O-norbornyldithioperoxydicarbonic acid;O,O′-diphenyldithioperoxydicarbonic acid;O,O′-dibenzyldithioperoxydicarbonic acid;O,O′-dicyclohexyldithioperoxydicarbonic acid; andO,O′-dinorbornyldithioperoxydicarbonic acid.

O Valence Stabilizer #2: Examples of imidodiphosphonic acids,hydrazidodiphosphonic acids, bis(imidodiphosphonic acids),bis(hydrazidodiphosphonic acids), poly(imidodiphosphonic acids),poly(hydrazidodiphosphonic acids), and derivatives thereof (O—OBidentates, O—O Tridentates, O—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: imidodiphosphonic acid,methylimidodiphosphonic acid, isopropylimidodiphosphonic acid,tert-butylimidodiphosphonic acid, phenylimidodiphosphonic acid,pentafluorophenylimidodiphosphonic acid, benzylimidodiphosphonic acid,cyclohexylimidodiphosphonic acid, norbornylimidodiphosphonic acid,dimethylimidodiphosphonic acid, diisopropylimidodiphosphonic acid,di-tert-butylimidodiphosphonic acid, diphenylimidodiphosphonic acid,di-pentafluorophenylimidodiphosphonic acid, dibenzylimidodiphosphonicacid, dicyclohexylimidodiphosphonic acid, anddinorbornylimidodiphosphonic acid. [Note: the phosphite (P⁺³) valence ofthe phosphorus atom makes stabilizization of high valence metal ionsmuch more difficult, though still possible.]

O Valence Stabilizer #3: Examples of imidodiphosphonamides,hydrazidodiphosphonamides, bis(imidodiphosphonamides),bis(hydrazidodiphosphonamides), poly(imidodiphosphonamides), andpoly(hydrazidodiphosphonamides) (O—O Bidentates, O—O Tridentates, O—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:imidodiphosphonamide, N-methylimidodiphosphonamide,N-isopropylimidodiphosphonamide, N-tert-butylimidodiphosphonamide,N-phenylimidodiphosphonamide, N-pentafluorophenylimidodiphosphonamide,N-benzylimidodiphosphonamide, N-cyclohexylimidodiphosphonamide,N-norbornylimidodiphosphonamide, N,N′″-dimethylimidodiphosphonamide,N,N′″-diisopropylimidodiphosphonamide,N,N′″-di-tert-butylimidodiphosphonamide,N,N′″-diphenylimidodiphosphonamide,N,N′″-di-pentafluorophenylimidodiphosphonamide,N,N′″-dibenzylimidodiphosphonamide,N,N′″-dicyclohexylimidodiphosphonamide, andN,N′″-dinorbornylimidodiphosphonamide. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

O Valence Stabilizer #4: Examples of diphosphonamides,bis(diphosphonamides), and poly(diphosphonamides) (O—O Bidentates, O—OTridentates, O—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: diphosphonamide, N-methyldiphosphonamide,N-isopropyldiphosphonamide, N-tert-butyldiphosphonamide,N-phenyldiphosphonamide, N-pentafluorophenyldiphosphonamide,N-benzyldiphosphonamide, N-cyclohexyldiphosphonamide,N-norbornyldiphosphonamide, N,N′″-dimethyldiphosphonamide,N,N′″-diisopropyldiphosphonamide, N,N′″-di-tert-butyldiphosphonamide,N,N′″-diphenyldiphosphonamide,N,N′″-di-pentafluorophenyldiphosphonamide,N,N′″-dibenzyldiphosphonamide, N,N′″-dicyclohexyldiphosphonamide, andN,N′″-dinorbornyldiphosphonamide. [Note: the phosphite (P⁺³) valence ofthe phosphorus atom makes stabilizization of high valence metal ionsmuch more difficult, though still possible.]

O Valence Stabilizer #5: Examples of carbazates (carbazides),bis(carbazates), and poly(carbazates) (O—O Bidentates, O—O Tridentates,and O—O Tetradentates; or possibly N—O Bidentates, N—O Tridentates, andN—O Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N,N′-dimethylcarbazate; N,N′-di(trifluoromethyl)carbazate;N,N′-diethylcarbazate; N,N′-diphenylcarbazate; N,N′-dibenzylcarbazate;N,N′-di(pentafluorophenyl)carbazate; N,N′-dicyclohexylcarbazate; andN,N′-dinorbornylcarbazate.

O Valence Stabilizer #6: Examples of arsonic acids, bis(arsonic acids),poly(arsonic acids), and derivatives thereof (O—O Bidentates, O—OTridentates, O—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: arsonic acid, O-phenylarsonic acid, O-benzylarsonic acid,O-cyclohexylarsonic acid, O-norbornylarsonic acid, O,O-diphenylarsonicacid, O,O-dibenzylarsonic acid, O,O-dicyclohexylarsonic acid,O,O-dinorbornylarsonic acid; and aminophenylarsonic acids.

O Valence Stabilizer #7: Examples of alkyl- and aryl-borates andbis(borates) (O—O Bidentates and O—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: triethyl borate; diisopropyl borate;diphenyl borate; dibenzyl borate; dicyclohexyl borate; and dinorbornylborate.

O Valence Stabilizer #8: Examples of alkyl- and aryl-boronates andbis(boronates) (O—O Bidentates and O—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: diethyl boronate; diisopropyl boronate;diphenyl boronate; dibenzyl boronate; dicyclohexyl boronate; anddinorbornyl boronate. [Note: boronates tend to stabilize lower oxidationstates in metal ions.]

O Valence Stabilizer #9: Examples of phosphine P-oxides andamino-substituted phosphine oxides (O Monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trimethylphosphine oxide (TMPO);triethylphosphine oxide (TEPO); triphenylphosphine oxide (TPhPO);tribenzylphosphine oxide (TBzPO); tricyclohexylphosphine oxide (TcHxPO);and trinorbornylphosphine oxide for phosphine P-oxides; andhexamethylphosphoramide (HMPA); trimorpholinophosphine oxide (TMrPO);tripiperidinophosphine oxide; tripyrrolidinophosphine oxide; andtri(cyclohexylamino)phosphine oxide for amino-substituted phosphineoxides.

O Valence Stabilizer #10: Examples of arsine As-oxides andamino-substituted arsine oxides (O Monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trimethylarsine oxide (TMAsO);triethylarsine oxide (TEAsO); triphenylarsine oxide (TPhAsO);tribenzylarsine oxide (TBzAsO); tricyclohexylarsine oxide (TcHxAsO); andtrinorbornylarsine oxide for arsine As-oxides; and hexamethylarsonamide;trimorpholinoarsine oxide; tripiperidinoarsine oxide;tripyrrolidinoarsine oxide; and tri(cyclohexylamino)arsine oxide foramino-substituted arsine oxides.

O Valence Stabilizer #11a: Examples of 5-membered heterocyclic ringscontaining one oxygen atom (O monodentate) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: furan, dihydrofuran, oxazole, isoxazole, oxadiazole,oxatriazole, oxathiole, benzofuran, benzodihydrofuran, benzoxazole,benzisoxazole, benzoxadiazole (benzofurazan), dibenzofuran,dibenzoxazole, dibenzisoxazole, naphthofuran, naphthoxazole,naphthisoxazole, and naphthoxadiazole.

O Valence Stabilizer #11b: Examples of 5-membered heterocyclic ringscontaining two oxygen atoms (O monodentate or O—O bidentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dioxolane, benzodioxolane, andnaphthodioxolane.

O Valence Stabilizer #12a: Examples of 6-membered heterocyclic ringscontaining one oxygen atom (O monodentate) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: dihydropyran, pyran, oxazine, oxadiazine, oxatriazine,oxathiin, benzopyran, benzoxazine, benzoxadiazine, dibenzopyran,naphthopyran, naphthoxazine, and naphthoxadiazine.

O Valence Stabilizer #12b: Examples of 6-membered heterocyclic ringscontaining two oxygen atoms (O monodentate or O—O bidentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dihydrodioxane, dioxane, benzodioxane,dibenzodioxane, and naphthodioxane.

O Valence Stabilizer #13a: Examples of 5-membered heterocyclic ringscontaining one oxygen atom and having at least one additional oxygenatom binding site not contained in a ring (O monodentates, O—Obidentates, O—O tridentates, O—O tetradentates, or O—O hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2,5-dihydroxy-2,5-dihydrofuran; 2,5-bis(hydroxymethyl)-2,5-dihydrofuran;2,5-bis(2-hydroxyphenyl)-2,5-dihydrofuran; 2,5-dihydroxyfuran;2,5-bis(hydroxymethyl)furan; and 2,5-bis(2-hydroxyphenyl)furan.

O Valence Stabilizer #13b: Examples of 5-membered heterocyclic ringscontaining two oxygen atoms and having at least one additional oxygenatom binding site not contained in a ring (O monodentates, O—Obidentates, O—O tridentates, O—O tetradentates, or O—O hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-hydroxy-1,3-dioxolane;2-hydroxymethyl)-1,3-dioxolane; 4,5-dihydroxy-1,3-dioxolane;4,5-bis(2-hydroxyphenyl>1,3-dioxolane; 2-hydroxybenzodioxolane; and7-hydroxybenzodioxolane.

O Valence Stabilizer #14a: Examples of 6-membered heterocyclic ringscontaining one oxygen atom and having at least one additional oxygenatom binding site not contained in a ring (O monodentates, O—Obidentates, O—O tridentates, O—O tetradentates, or O—O hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2,6-dihydroxy-2,5-dihydropyran; 2,6-bis(hydroxymethyl)-2,5-dihydropyran;2,6-bis(2-hydroxyphenyl)-2,5-dihydropyran; 2,6-dihydroxypyran;2,6-bis(hydroxymethyl)pyran; 2,6-bis(2-hydroxyphenyl)pyran;2-hydroxy-1-benzopyran; 8-hydroxy-1-benzopyran; and1,9-dihydroxydibenzopyran.

O Valence Stabilizer #14b: Examples of 6-membered heterocyclic ringscontaining two oxygen atoms and having at least one additional oxygenatom binding site not contained in a ring (O monodentates, O—Obidentates, O—O tridentates, O—O tetradentates, or O—O hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-hydroxy-1,4-dioxane;2,6-dihydroxy-1,4-dioxane; 2,6-bis(2-hydroxyphenyl)-1,4-dioxane;2,3-dihydroxy-1,4-benzodioxane; 5,8-dihydroxy-1,4-benzodioxane;1,8-dibydroxydibenzodioxane; and 1,4,5,8-tetrahydroxydibenzodioxane.

O Valence Stabilizer #15a: Examples of 5-membered heterocyclic ringscontaining one oxygen atom and having at least one additional oxygenatom binding site contained in a ring (O monodentates, O—O bidentates,O—O tridentates, O—O tetradentates, or O—O hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-2,5-dihydrofuran;2,2′,2″-tri-2,5-dihydrofuran; 2,2′-bifuran; 2,2′,2″-trifuran;1,1′-bis(dibenzofuran); and polyfurans.

O Valence Stabilizer #15b: Examples of 5-membered heterocyclic ringscontaining two oxygen atoms and having at least one additional oxygenatom binding site contained in a ring (O monodentates, O—O bidentates,O—O tridentates, O—O tetradentates, or O—O hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-1,3-dioxolane;4,4′-bi-1,3-dioxolane; 7,7′-bi-1,2-benzodioxolane; and3,3′-bi-1,2-benzodioxolane.

O Valence Stabilizer #16a: Examples of 6-membered heterocyclic ringscontaining one oxygen atom and having at least one additional oxygenatom binding site contained in a ring (O monodentates, O—O bidentates,O—O tridentates, O—O tetradentates, or O—O hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-2,5-dihydropyran;2,2′,2″-tri-2,5-dihydropyran; 2,2′-bipyran; 2,2′,2″-tripyran; and1,1′-bis(dibenzopyran).

O Valence Stabilizer #16b: Examples of 6-membered heterocyclic ringscontaining one oxygen atom and having at least one additional oxygenatom binding site contained in a ring (O monodentates, O—O bidentates,O—O tridentates, O—O tetradentates, or O—O hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-1,4-dioxane;2,2′-bi-1,3-dioxane; 5,5′-bi-1,4-benzodioxane; and2,2′-bi-1,3-benzodioxane.

O Valence Stabilizer #17a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofoxygen (usually ester or hydroxyl groups) and are not contained incomponent heterocyclic rings (O—O Bidentates, O—O Tridentates, O—OTetradentates, and O—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 8-crown-4; 10-crown-4; 12-crown-4; 14-crown-4; 16-crown-4;18-crown-4; 20-crown-4; dibenzo-8-crown-4; dibenzo-10-crown-4;dibenzo-12-crown-4; dibenzo-14-crown-4; dibenzo-16-crown-4;dibenzo-18-crown-4; dibenzo-20-crown-4; tetrabenzo-8-crown-4;tetrabenzo-10-crown-4; tetrabenzo-12-crown-4; tetrabenzo-14-crown-4;tetrabenzo-16-crown-4; tetrabenzo-18-crown-4; and tetrabenzo-20-crown-4.

O Valence Stabilizer #17b: Examples of five-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofoxygen (usually ester or hydroxyl groups) and are not contained incomponent heterocyclic rings (O—O Bidentates, O—O Tridentates, O—OTetradentates, and O—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 10-crown-5; 15-crown-5; 20-crown-5; 25-crown-5;pentabenzo-10-crown-5; pentabenzo-15-crown-5; pentabenzo-20-crown-5; andpentabenzo-25-crown-5.

O Valence Stabilizer #17c: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofoxygen (usually ester or hydroxyl groups) and are not contained incomponent heterocyclic rings (O—O Bidentates, O—O Tridentates, O—OTetradentates, and O—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 12-crown-6; 18-crown-6; 24-crown-6; 30-crown-6; 36-crown-6;tribenzo-12-crown-6; tribenzo-18-crown-6; tribenzo-24-crown-6;tribenzo-30-crown-6; tribenzo-36-crown-6; hexabenzo-12-crown-6;hexabenzo-18-crown-6; hexabenzo-24-crown-6; hexabenzo-30-crown-6; andhexabenzo-36-crown-6.

O Valence Stabilizer #17d: Examples of seven-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofoxygen (usually ester or hydroxyl groups) and are not contained incomponent heterocyclic rings (O—O Bidentates, O—O Tridentates, O—OTetradentates, and O—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 14-crown-7; 21-crown-7; 28-crown-7; 35-crown-7;heptabenzo-14-crown-7; heptabenzo-21-crown-7; heptabenzo-28-crown-7; andheptabenzo-35-crown-7.

O Valence Stabilizer #17e: Examples of eight-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofoxygen (usually ester or hydroxyl groups) and are not contained incomponent heterocyclic rings (O—O Bidentates, O—O Tridentates, O—OTetradentates, and O—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 16-crown-8; 24-crown-8; 32-crown-8; 40-crown-8; 48-crown-8;tetrabenzo-16-crown-8; tetrabenzo-24-crown-8; tetrabenzo-32-crown-8;tetrabenzo-40-crown-8; tetrabenzo-48-crown-8; octabenzo-16-crown-8;octabenzo-24-crown-8; octabenzo-32-crown-8; octabenzo-40-crown-8; andoctabenzo-48-crown-8.

O Valence Stabilizer #17f: Examples of ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofoxygen (usually ester or hydroxyl groups) and are not contained incomponent heterocyclic rings (O—O Bidentates, O—O Tridentates, O—OTetradentates, and O—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 20-crown-10; 30-crown-10; 40-crown-10; 50-crown-10;pentabenzo-20-crown-10; pentabenzo-30-crown-10; pentabenzo-40-crown-10;and pentabenzo-50-crown-10.

O Valence Stabilizer #18: Examples of four-, five-, six-, seven-,eight-, and ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of oxygen and arecontained in component 5-membered heterocyclic rings (O—O Bidentates,O—O Tridentates, O—O Tetradentates, and O—O Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetrafurans, tetrabenzofurans;pentafurans; pentabenzofurans; hexafurans; hexabenzofurans; heptafurans;heptabenzofurans; octafurans; octabenzofurans; decafurans; anddecabenzofurans.

O Valence Stabilizer #19: Examples of four-, five-, six-, seven-,eight-, and ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of oxygen and arecontained in component 6-membered heterocyclic rings (O—O Bidentates,O—O Tridentates, O—O Tetradentates, and O—O Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetrapyrans, tetrabenzopyrans;pentapyrans; pentabenzopyans; hexapyans; hexabenzopyans; heptapyans;heptabenzopyans; octapyans; octabenzopyans; decapyans; anddecabenzopyans.

N—S Valence Stabilizer #1: Examples of thioimidates, dithioimidates,polythioimidates, and derivatives of thioimidic acid (N—S bidentates andN—S tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: S-methylformathioimidate; S-ethyl formathioimidate; S-methyl acetathioimidate;S-ethyl acetathioimidate; S-methyl benzthioimidate; S-ethylbenzthioimidate; S-methyl cyclohexylthioimidate; S-ethylcyclohexylthioimidate; S-methyl pentafluorobenzthioimidate; S-ethylpentafluorobenzthioimidate; S-methyl 2-pyridylthioimidate; S-ethyl2-pyridylthioimidate; S,S′-dimethyl benzdithioimidate; S,S′-dimethyltetrafluorobenzdithioimidate; 2-iminothiolane; and2-iminotetrahydrothiopyran. [Note: many thioimidate complexes aredecomposed by water, but their stability can be enhanced through the useof fluorinated solubility control anions (e.g., PF₆ ⁻).]

N—S Valence Stabilizer #2: Examples of thioguanylureas,guanidinothioureas, bis(thioguanylureas), bis(guanidinothioureas,poly(thioguanylureas), and poly(guanidinothioureas) (N—S Bidentates andN—S Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:thioguanylurea (amidinothiourea); guanidinothiourea;methylthioguanylurea; ethylthioguanylurea; isopropylthioguanylurea;butylthioguanylurea; benzylthioguanylurea; phenylthioguanylurea;tolylthioguanylurea; naphthylthioguanylurea; cyclohexylthioguanylurea;norbornylthioguanylurea; adamantylthioguanylurea; dimethylthioguangurea;diethylthioguanylurea; diisopropylthioguanylurea; dibutylthioguanylurea;dibenzylthioguanylurea; diphenylthioguanylurea; ditolylthioguanylurea;dinaphthylthioguanylurea; dicyclohexylthioguanylurea;dinorbornylthioguanylurea; diadamantylthioguanylurea;ethylenebis(thioguanylurea); propylenebis(thioguanylurea);phenylenebis(thioguanylurea); piperazinebis(thioguanylurea);oxalylbis(thioguanylurea); malonylbis(thioguanylurea);succinylbis(thioguanylurea); and phthalylbis(thioguanylurea). [Note:thioguanylureas generally tend to favor lower oxidation states incomplexed metals.]

N—S Valence Stabilizer #3: Examples of amidinothioamides,guanidinothioamides, bis(amidinothioamides), bis(guanidinothioamides),poly(amidinothioamides), and poly(guanidinothioamides) (including bothN-amidinothioamides and 2-amidinothioacetamides) (N—S Bidentates, N—STridentates, and N—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: amidinothioacetamide; guanidinothioamide,amidinothiopropanamide; amidinothiobutanamide; amidinothiobenzamide;amidinothiotoluamide; amidinothiocyclohexamide;N-methylamidinothioacetamide; N-ethylamidinothiopropanamide;N-propylamidinothiobutanamide; N-phenylamidinothiobenzamide;N-tolylamidinothiotoluamide; N-cyclohexylamidinothiocyclohexamide;bis(amidinothiooxamide); bis(amidinothiomalonamide);bis(amidinothiosuccinamide); bis(amidinothiophthalamide);2-amidinothioacetamide (thiomalonamamidine);N-methyl-2-amidinothioacetamide; N-ethyl-2-amidinothioacetamide;N-phenyl-2-amidinothioacetamide; N-benzyl-2-amidinothioacetamide;N-cyclohexyl-2-amidinothioacetamide;N,N′-dimethyl-2-amidinothioacetamide;N,N′-diethyl-2-amidinothioacetamide;N,N′-diphenyl-2-amidinothioacetamide;N,N′-dibenzyl-2-amidinothioacetamide; andN,N′-dicyclohexyl-2-amidinothioacetamide. [Note: amidinothioamidesgenerally tend to favor lower oxidation states in complexed metals.]

N—S Valence Stabilizer #4: Examples of imidoylthioamides,bis(imidoylthioamides), and poly(imidoylthioamides) (N—S Bidentates, N—STridentates, and N—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: acetimidoylthioacetamide; acetimidoylthiopropanamide;acetimidoylthiobutanamide; acetimidoylthiobenzamide;acetimidolylthiotoluamide; acetimidoylthiocyclohexamide;propimidoylthiopropanamide; butimidoylthiobutanamide;benzimidoylthiobenzamide; ethylenebis(acetimidoylthioacetamide);propylenebis(acetimidoylthioacetamide); andphenylenebis(acetimidoylthioacetamide). [Note: imidoylthioamidesgenerally tend to favor lower oxidation states in complexed metals.]

N—S Valence Stabilizer #5: Examples of thioureas, bis(thioureas), andpoly(thioureas), including thiourylene complexes (N—S bidentates and N—Stetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: thiourea;methylthiourea; ethylthiourea; isopropylthiourea; benzylthiourea;phenylthiourea; cyclohexylthiourea; naphthylthiourea (ntu);biphenylthiourea; norbornylthiourea; adamantylthiourea;N,N′-dimethylthiourea; N,N′-diethylthiourea; N,N′-diisopropylthiourea;N,N′-dibenzylthiourea; N,N′-dicyclohexylthiourea;N,N′-dinapthylthiourea; N,N′-dibiphenylthiourea;N,N′-dinorbornylthiourea; N,N′-diadamantylthiourea; tetramethylthiourea;ethylenethiourea (2-imidazolidinethione)(etu);4,5-dihydroxy-2-imidazolinethione (dhetu); propylenethiourea;N-(thiazol-2-yl)thiourea; diphenylphosphinothioyl thioureas;allylthiourea; N-allyl-N′-pyridylthiourea; N-allyl-N′-anisylthiourea;N-allyl-N′-naphthylthiourea; N-allyl-N′-phenylthiourea; thioglycoluril(acetylenethiourea); and bis(pyridylmethyl)thiourea. [Note: thioureasgenerally tend to favor lower oxidation states in complexed metals.]

N—S Valence Stabilizer #6: Examples of thiocarboxamides,bis(thiocarboxamides), and poly(thiocarboxamides), (N—S bidentates, N—Stridentates, and N—S tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: thiocarbamide (tu); thioacetamide (taa); thiopropionamide;thiobutanamide; thiobenzamide (1-phenylthioformamide)(tba);1-naphthylthioformamide; 1-cyclohexylthioformamide);1-norbornylthioformamide; 1-adamantylthioformamide;N,N-dimethylthioformamide; N,N-dimethylthioacetamide;pyridine-2-thiocarboxamide (thiopicolinamide);pyrazine-2,3-dithiocarboxamide; thionicotinamide;2-thiophenethiocarboxamide; N,N-dimethylthiobenzamide;N-ethylthiocarbamide (N-etu); tetramethylthiocarbamide (tmtu);2-thioacetamidothiazole (tatz); and polythioacrylamides. [Note:thiocarboxamides generally tend to favor lower oxidation states incomplexed metals.]

N—S Valence Stabilizer #7: Examples of imidosulfurous diamides andbis(imidosulfurous diamides) (N—S Bidentates, N—S Tridentates, and N—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N,N′-diphenylimidosulfurous diamide; N,N′-dibenzylimidosulfurousdiamide; and phenylenebis(imidosulfurous diamide). [Note: thesecomplexes tend to hydrolyze unless stabilized with a fluorinated anionicsolubility control agent. The sulfite (S⁺⁴) valence of the sulfur atommakes stabilizization of high valence metal ions much more difficult,though still possible.]

N—S Valence Stabilizer #8: Examples of sulfurdiimines,bis(sulfurdiimines), and poly(sulfurdiimines) (N—S Bidentates, N—STridentates, and N—S Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: N,N′-diphenylsulfurdiimine; N,N′-dibenzylsulfurdiimine; andphenylenebis(sulfurdiimine). [Note: these complexes tend to hydrolyzeunless stabilized with a fluorinated anionic solubility control agent.The sulfite (S⁺⁴) valence of the sulfur atom makes stabilizization ofhigh valence metal ions much more difficult, though still possible.]

N—S Valence Stabilizer #9: Examples of phosphonimidothioic acid,phosphonimidodithioic acid, bis(phosphonimidothioic acid);bis(phosphonimidodithioic acid), and derivatives thereof (N—SBidentates, N—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphonimidothioic acid, phosphonimidodithioic acid;O-phenylphosphonimidothioic acid; O-benzylphosphonimidothioic acid;O-cyclohexylphosphonimidothioic acid; O-norbornylphosphonimidothioicacid; S-phenylphosphonimidodithioic acid; S-benzylphosphonimidodithioicacid; S-cyclohexylphosphonimidodithioic acid; andS-norbornylphosphonimidodithioic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

N—S Valence Stabilizer #10: Examples of phosphonothioic diamides,bis(phosphonothioic diamides), and poly(phosphonothioic diamides) (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphonothioic diamide, phosphonothioic dihydrazide,phosphonamidothioic hydrazide, N-phenylphosphonothioic diamide,N-benzylphosphonothioic diamide, N-cyclohexylphosphonothioic diamide,and N-norbornylphosphonothioic diamide. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

N—S Valence Stabilizer #11: Examples of phosphonamidothioic acid,phosphonamidimidodithioic acid, bis(phosphonamidothioic acid),bis(phosphonamidimidodithioic acid), poly(phosphonamidothioic acid), andpoly(phosphonamidimidodithioic acid), and derivatives thereof (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: phosphonamidothioic acid, phosphonamidimidodithioic acid,phosphonohydrazidodithioic acid, phosphonohydrazidothioic acid,S-phenylphosphonamidimidodithioic acid,S-benzylphosphonamidimidodithioic acid,S-cyclohexylphosphonamidimidodithioic acid, andS-norbornylphosphonamidimidodithioic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

N—S Valence Stabilizer #12: Examples of beta-aminothiones (N-substituted3-amino-2-propenethioaldehydes), bis(beta-aminothiones), andpoly(beta-aminothiones) (N—S Bidentates and N—S Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 4-methylamino-3-penten-2-thione;4-ethylamino-3-penten-2-thione; 4-isopropylamino-3-penten-2-thione;4-phenylamino-3-penten-2-thione; 4-naphthylamino-3-penten-2-thione;4-cyclohexylamino-3-penten-2-thione; 4-norbornylamino-3-penten-2-thione;4-hydroxyamino-3-penten-2-thione;3-methylamino-1-phenyl-2-butenethioaldehydel;3-ethylamino-1-phenyl-2-butenethioaldehyde;3-isopropylamino-1-phenyl-2-butenethioaldehyde;3-phenylamino-1-phenyl-2-butenethioaldehyde;3-naphthylamino-1-phenyl-2-butenethioaldehyde;3-cyclohexylamino-1-phenyl-2-butenethioaldehyde;3-norbornylamino-1-phenyl-2-butenethioaldehyde;3-hydroxyamino-1-phenyl-2-butenethioaldehyde;3-phenylamino-1,3-diphenyl-2-propenethioaldehyde;3-cyclohexylamino-1,3-dicyclohexyl-2-propenethioaldehyde; and3-norbornylamino-1,3-dinorbornyl-2-propenethioaldehyde.

N—S Valence Stabilizer #13: Examples of 3-aminothioacrylamides(3-amino-2-thiopropenamides), 3,3-diaminothioacrylamides,bis(3-aminothioacrylamides), bis(3,3-diaminothioacrylamides),poly(3-aminothioacrylamides), and poly(3,3-diaminothioacrylamides) (N—SBidentates and N—S Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 3-methylaminothioacrylamide; 3-ethylaminothioacrylamide,3-isopropylaminothioacrylamide, 3-phenylaminothioacrylamide;3-naphthylaminothioacrylamide; 3-cyclohexylaminothioacrylamide;3-norbornylaminothioacrylamide; 3-hydroxyaminothioacrylamide;N-methyl-3-methylaminothioacrylamide;N-ethyl-3-ethylaminothioacrylamide,N-isopropyl-3-isopropylaminothioacrylamide,N-phenyl-3-phenylaminothioacrylamide;N-naphthyl-3-naphthylaminothioacrylamide;N-cyclohexyl-3-cyclohexylaminothioacrylamide;N-norbornyl-3-norbornylaminothioacrylamide;3-amino-3-methylaminothioacrylamide; 3-amino-3-ethylaminothioacrylamide,3-amino-3-isopropylaminothioacrylamide,3-amino-3-phenylaminothioacrylamide;3-amino-3-naphthylaminothioacrylamide;3-amino-3-cyclohexylaminothioacrylamide;3-amino-3-norbornylaminothioacrylamide; and3-amino-3-hydroxyaminothioacrylamide.

N—S Valence Stabilizer #14: Examples of 3-aminothioacrylic acids(3-amino-2-thiopropenoic acids), 3-mercapto-3-aminothioacrylic acids,bis(3-aminothioacrylic acids), bis(3-mercapto-3-aminothioacrylic acids),poly(3-aminothioacrylic acids), and poly(3-mercapto-3-aminothioacrylicacids), and derivatives thereof (N—S Bidentates and N—S Tetradentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 3-aminothioacrylic acid;3-mercapto-3-aminothioacrylic acid; 3-methylaminothioacrylic acid;3-ethylaminothioacrylic acid; 3-isopropylaminothioacrylic acid;3-phenylaminothioacrylic acid; 3-naphthylaminothioacrylic acid;3-cyclohexylaminothioacrylic acid; 3-norbornylaminothioacrylic acid;3-hydroxyaminothioacrylic acid; methyl 3-methylaminothioacrylate; ethyl3-ethylaminothioacrylate; isopropyl 3-isopropylaminothioacrylate; benzyl3-phenylaminothioacrylate; naphthyl 3-naphthylaminothioacrylate;cyclohexyl 3-cyclohexylaminothioacrylate; and norbornyl3-norbornylaminothioacrylate.

N—S Valence Stabilizer #15: Examples of N-thioacyl benzylidenimines,bis(N-thioacyl benzylidenimines), and poly(N-thioacyl benzylidenimines)(N—S Bidentates and N—S Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: N-thioformyl benzylidenimine, N-thioacetyl benzylidenimine;N-thiobenzoyl benzylidenimine; and N-pentafluorothiobenzoylbenzylidenimine.

N—S Valence Stabilizer #16: Examples of thiocarbonyl oximes,bis(thiocarbonyl oximes), and poly(thiocarbonyl oximes) (N—S Bidentates,N—S Tridentates, and N—S Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: butane-3-thione-2-one monoxime); anddiphenylethane-2-thione-1-one monoxime.

N—S Valence Stabilizer #17: Examples of mercapto oximes, bis(mercaptooximes), and poly(mercapto oximes) (including 2-sulfur heterocyclicoximes) (N—S Bidentates, N—S Tridentates, N—S Tetradentates, and N—SHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:3-mercaptobutan-2-one oxime; 4-mercaptohexan-3-one oxime;(1,2-diphenyl-2-mercaptoethanone oxime);1,2-di(trifluoromethyl)-2-mercaptoethanone oxime;1,2-dicyclohexyl-2-mercaptoethanone oxime;1,2-dinorbornyl-2-mercaptoethanone oxime; 2-mercaptobenzaldehyde oxime;2-mercapto-1-naphthaldehyde oxime; thiophene-2-aldoxime; methyl2-thiophenyl ketoxime; and phenyl 2-thiophenyl ketoxime.

N—S Valence Stabilizer #18: Examples of 2-nitrothiophenols(2-nitrobenzenethiols) (N—S Bidentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-nitrothiophenol; 2,3-dinitrothiophenol;2,4-dinitrothiophenol; 2,5-dinitrothiophenol; 2,6-dinitrothiophenol;1-nitro-2-naphthalenethiol; and 2-nitro-1-naphthalenethiol.

N—S Valence Stabilizer #19: Examples of 2-nitrilothiophenols(2-nitrilobenzenethiols) (N—S Bidentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-cyanothiophenol; 2,3-dicyanothiophenol;2,4-dicyanothiophenol; 2,5-dicyanothiophenol; 2,6-dicyanothiophenol;1-cyano-2-naphthalenethiol; and 2-cyano-1-naphthalenethiol.

N—S Valence Stabilizer #20: Examples of thiohydrazides,bis(thiohydrazides), and poly(thiohydrazides) (N—S Bidentates and N—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: thioformichydrazide; thioacetic hydrazide; thiopropionic hydrazide; thiobenzoichydrazide; thiophthalhydrazide; thiosalicylic hydrazide; thionaphthoichydrazides; thionorbornaneacetic hydrazide; thionicotinic hydrazide; andthioisonicotinic hydrazide. [Note: thiohydrazides prefer complexationwith lower oxidation states in metal ions.]

N—S Valence Stabilizer #21: Examples of thiosemicarbazides,bis(thiosemicarbazides), and poly(thiosemicarbazides) (N—S Bidentates,N—S Tetradentates, and N—S Hexadentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: thiosemicarbazide (tsc); thiosemicarbazide diacetic acid(tsda); 1-methylthiosemicarbazide (1 mts); 1-ethylthiosemicarbazide;1-isopropylthiosemicarbazide; 1-phenylthiosemicarbazide (1pts)(cryogenine); 1-benzylthiosemicarbazide;1-cyclohexylthiosemicarbazide; 1-norbornylthiosemicarbazide;4-methylthiosemicarbazide (4 mts); 4-ethylthiosemicarbazide;4-isopropylthiosemicarbazide; 4-phenylthiosemicarbazide (4-pts);4-benzylthiosemicarbazide; 4-cyclohexylthiosemicarbazide;4-norbornylthiosemicarbazide; nicotinic thiosemicarbazide; isonicotinicthiosemicarbazide; and 4-phenyl-1-benzenesulfonyl-3-thiosemicarbazide(pbst). [Note: thiosemicarbazides prefer complexation with loweroxidation states in metal ions.]

N—S Valence Stabilizer #22: Examples of five-, seven-, or nine-memberedmacrocyclics, macrobicyclics, and macropolycyclics (includingcatapinands, cryptands, cyclidenes, and sepulchrates) wherein allbinding sites are composed of nitrogen (usually amine or imine groups)or sulfur (usually thiols, mercaptans, or thiocarbonyls) and are notcontained in component heterocyclic rings (N—S Tridentates, N—STetradentates, and N—S Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: triazadithiacyclodecane ([10]aneS₂N₃);triazadithiacycloundecane ([11]aneS₂N₃); triazadithiacyclododecane([12]aneS₂N₃); triazadithiacyclotridecane ([13]aneS₂N₃);triazadithiacyclotetradecane ([14]aneS₂N₃); triazadithiacyclopentadecane([15]aneS₂N₃thiomorpholine; and thiazolidine.

N—S Valence Stabilizer #23: Examples of five- or seven-memberedmacrocyclics, macrobicyclics, and macropolycyclics (includingcatapinands, cryptands, cyclidenes, and sepulchrates) wherein allbinding sites are composed of nitrogen or sulfur and are contained incomponent heterocyclic rings (N—S Bidentates, N—S Tridentates, N—STetradentates, or N—S Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dithiopyrantripyridines; dithiophenetripyrroles;trithiopyrantetrapyridines; and trithiophenetetrapyrroles.

N—S Valence Stabilizer #24: Examples of five-, seven-, or nine-memberedmacrocyclics, macrobicyclics, and macropolycyclics (includingcatapinands, cryptands, cyclidenes, and sepulchrates) wherein allbinding sites are composed of nitrogen or sulfur and are contained in acombination of heterocyclic rings and amine, imine, thiol, mercapto, orthiocarbonyl groups (N—S Bidentates, N—S Tridentates, N—S Tetradentates,or N—S Hexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:azathiapentaphyrins; diazadithiapentaphyrins; azathiapentaphyrins; anddiazadithiapentaphyrins.

N—O Valence Stabilizer #1: Examples of imidates, diimidates,polyimidates, and derivatives of imidic acid (N—O bidentates and N—Otetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: O-methylformimidate; O-ethyl formimidate; O-methyl acetimidate; O-ethylacetimidate; O-methyl benzimidate; O-ethyl benzimidate; O-methylcyclohexylimidate; methyl cyclohexylimidate; O-methylpentafluorobenzimidate; O-ethyl pentafluorobenzimidate; O-methyl2-pyridylimidate; methyl 2-pyridylimidate; O,O′-dimethyl benzdiimidate;O,O′-dimethyl tetrafluorobenzdiimidate; 2-iminotetrahydrofuran; and2-iminotetrahydropyran. [Note: most imidate complexes are decomposed bywater, but their stability can be enhanced through the use offluorinated solubility control anions (e.g. PF₆ ⁻).]

N—O Valence Stabilizer #2: Examples of pseudoureas, bis(pseudoureas),and poly(pseudoureas) (N—O bidentates and N—O tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: O-methyl pseudourea; O-ethylpseudourea; O-isopropyl pseudourea; O-benzyl pseudourea; O-cyclohexylpseudourea; O-norbornyl pseudourea; O-pentafluorobenzyl pseudourea;N-methyl pseudourea; N-ethyl pseudourea; N-isopropyl pseudourea;N-benzyl pseudourea; N-cyclohexyl pseudourea; N-norbornyl pseudourea;and N-pentafluorobenzyl pseudourea.

N—O Valence Stabilizer #3: Examples of 2-amidinoacetates,bis(2-amidinoacetates), and poly(2-amidinoacetates) (N—O Bidentates andN—O Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N-methyl-2-amidinoacetate; O-methyl-2-amidinoacetate;N-benzyl-2-amidinoacetate; and O-benzyl-2-amidinoacetate. [Note: many2-amidinoacetates tend to hydrolyze in water. This can be minimizedthrough the use of fluorinated solubility control anions such as PF₆ ⁻.]

N—O Valence Stabilizer #4: Examples of ureas, bis(ureas), andpoly(ureas), including urylene complexes (N—O bidentates and N—Otetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: urea;methylurea; ethylurea; isopropylurea; benzylurea; cyclohexylurea;naphthylurea; biphenylurea; norbornylurea; adamantylurea;N,N′-dimethylurea; N,N′-diethylurea; N,N′-diisopropylurea;N,N′-dibenzylurea; N,N′-dicyclohexylurea; N,N′-dinapthylurea;N,N′-dibiphenylurea; N,N′-dinorbornylurea; N,N′-diadamantylurea;ethyleneurea (2-imidazolidone); propyleneurea; glycoluril(acetyleneurea); and N,N′-bis(4-nitrophenyl)urea.

N—O Valence Stabilizer #5: Examples of phosphonimidic acid,bis(phosphonimidic acid), poly(phosphonimidic acid), and derivativesthereof (N—O Bidentates and N—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphonimidic acid;O-phenylphosphonimidic acid; O-benzylphosphonimidic acid;O-cyclohexylphosphonimidic acid; and O-norbornylphosphonimidic acid.[Note: the phosphite (P⁺³) valence of the phosphorus atom makesstabilizization of high valence metal ions much more difficult, thoughstill possible.]

N—O Valence Stabilizer #6: Examples of phosphonamidic acid, phosphonicdiamide, bis(phosphonamidic acid), bis(phosphonic diamide),poly(phosphonamidic acid), poly(phosphonic diamide), and derivativesthereof (N—O Bidentates and N—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphonamidic acid, phosphonicdiamide, phosphonamidic hydrazide, phosphonic dihydrazide,O-phenylphosphonamidic acid, O-benzylphosphonamidic acid,O-cyclohexylphosphonamidic acid, O-norbornylphosphonamidic acid,N-benzylphosphonic diamide, N-phenylphosphonic diamide,N-cyclohexylphosphonic diamide, and N-norbornylphosphonic diamide.[Note: the phosphite (P⁺³) valence of the phosphorus atom makesstabilizization of high valence metal ions much more difficult, thoughstill possible.]

N—O Valence Stabilizer #7: Examples of beta-ketoamines (N-substituted3-amino-2-propenals), bis(beta-ketoamines), and poly(beta-ketoamines)(N—O Bidentates and N—O Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 4-methylamino-3-penten-2-one; 4-ethylamino-3-penten-2-one;4-isopropyl amino-3-penten-2-one; 4-phenylamino-3-penten-2-one;4-naphthylamino-3-penten-2-one; 4-cyclohexylamino-3-penten-2-one;4-norbornylamino-3-penten-2-one; 4-hydroxyamino-3-penten-2-one;3-methylamino-1-phenyl-2-butenal; 3-ethylamino-1-phenyl-2-butenal;3-isopropylamino-1-phenyl-2-butenal; 3-phenylamino-1-phenyl-2-butenal;3-naphthylamino-1-phenyl-2-butenal;3-cyclohexylamino-1-phenyl-2-butenal;3-norbornylamino-1-phenyl-2-butenal; 3-hydroxyamino-1-phenyl-2-butenal;3-phenylamino-1,3-diphenyl-2-propenal;3-cyclohexylamino-1,3-dicyclohexyl-2-propenal;3-norbornylamino-1,3-dinorbornyl-2-propenal; 2,2′-pyridil;alpha-pyridoin; 4-aminoantipyrine (aap); beta-phenylaminopropiophenone;and polyaminoquinones (PAQs).

N—O Valence Stabilizer #8: Examples of 3-aminoacrylamides(3-amino-2-propenamides), 3,3-diaminoacrylamides,bis(3-aminoacrylamides), bis(3,3-diaminoacrylamides),poly(3-aminoacrylamides), and poly(3,3-diaminoacrylamides) (N—OBidentates and N—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: 3-methylaminoacrylamide; 3-ethylaminoacrylamide,3-isopropylaminoacrylamide, 3-phenylaminoacrylamide;3-naphthylaminoacrylamide; 3-cyclohexylaminoacrylamide;3-norbornylaminoacrylamide; 3-hydroxyaminoacrylamide;N-methyl-3-methylaminoacrylamide; N-ethyl-3-ethylaminoacrylamide,N-isopropyl-3-isopropylaminoacrylamide,N-phenyl-3-phenylaminoacrylamide; N-naphthyl-3-naphthylaminoacrylamide;N-cyclohexyl-3-cyclohexylaminoacrylamide;N-norbornyl-3-norbornylaminoacrylamide; 3-amino-3-methylaminoacrylamide;3-amino-3-ethylaminoacrylamide, 3-amino-3-isopropylaminoacrylamide,3-amino-3-phenylaminoacrylamide; 3-amino-3-naphthylaminoacrylamide;3-amino-3-cyclohexylaminoacrylamide; 3-amino-3-norbornylaminoacrylamide;and 3-amino-3-hydroxyaminoacrylamide.

N—O Valence Stabilizer #9: Examples of 3-aminoacrylic acids(3-amino-2-propenoic acids), 3-hydroxy-3-aminoacrylic acids,bis(3-aminoacrylic acids), bis(3-hydroxy-3-aminoacrylic acids),poly(3-aminoacrylic acids), and poly(3-hydroxy-3-aminoacrylic acids),and derivatives thereof (N—O Bidentates and N—O Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 3-aminoacrylic acid;3-hydroxy-3-aminoacrylic acid; 3-methylaminoacrylic acid;3-ethylaminoacrylic acid; 3-isopropylaminoacrylic acid;3-phenylaminoacrylic acid; 3-naphthylaminoacrylic acid;3-cyclohexylaminoacrylic acid; 3-norbornylaminoacrylic acid;3-hydroxyaminoacrylic acid; methyl 3-methylaminoacrylate; ethyl3ethylaminoacrylate; isopropyl 3-isopropylaminoacrylate; benzyl3-phenylaminoacrylate; naphthyl 3-naphthylaminoacrylate; cyclohexyl3-cyclohexylaminoacrylate; and norbornyl 3-norbornylaminoacrylate.

N—O Valence Stabilizer #10: Examples of N-acyl benzylidenimines,bis(N-acyl benzylidenimines), and poly(N-acyl benzylidenimines) (N—OBidentates and N—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: N-formyl benzylidenimine, N-acetyl benzylidenimine; N-benzoylbenzylidenimine; and N-pentafluorobenzoyl benzylidenimine.

N—O Valence Stabilizer #11: Examples of 2-nitroanilines (N—O Bidentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: 2-nitroaniline;2,6-dintroaniline; 2-nitrophenylenediamine; 2-nitrophenylenetriamine;2-nitro-1-aminonaphthalene; 1-nitro-2-aminonaphthalene;nitrodiaminonaphthalene; and dipicrylamine.

N—O Valence Stabilizer #12: Examples of 2-nitrilophenols (N—OBidentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to: 2-cyanophenol;2,3-dicyanophenol; 2,4dicyanophenol; 2,5-dicyanophenol;2,6-dicyanophenol; 1-cyano-2-naphthol; and 2-cyano-1-naphthol. Alsoincludes acylcyanamides.

N—O Valence Stabilizer #13: Examples of amine N-oxides and N-diazineoxides (azoxy compounds) (N—O Bidentates, N—O Tridentates, and N—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: pyridineN-oxide (pyNO or PNO); picoline N-oxide (picNO); lutidine N-oxide (lutNOor LNO); collidine N-oxide (collNO or CNO); quinoline N-oxide (QuinNO orQNO); isoquinoline N-oxide (isoQuinNO or IQNO); acridine N-oxide (AcrNOor ANO); picolinic acid N-oxide (PicANO); pyridinethiolate N-oxide(PTNO); adenine N-oxide; adenosine N-oxide; 1,10-phenanthrolinemono-N-oxide (phenNO); 1,10-phenanthroline N,N-dioxide (phen2NO);bipyridyl mono-N-oxide (bipyNO); bipyridyl N,N-dioxide (bipy2NO);pyrazine mono-N-oxide (pyzNO); pyrazine N,N-dioxide (pyz2NO); pyrimidinemono-N-oxide (pymNO); pyrimidine N,N-dioxide (pym2NO); pyridazinemono-N-oxide (pdzNO); pyridazine N,N-dioxide (pdz2NO); quinoxalinemono-N-oxide (qxNO); quinoxaline N,N-dioxide (qx2NO); phenazinemono-N-oxide (phzNO); phenazine N,N-dioxide (phz2NO); 2,3-di(pyridineN-oxide)quinoxaline (dpoq); inosine N-oxide; 4,4′-bipyridineN,N-dioxide; 1-hydroxypyrazole 2-oxide; 1-hydroxyimidazole 3-oxide;2,2′-diimidazyl 3,3′-dioxide; imidazole N-oxides(1-hydroxyimidazole-3-N-oxides); N-benzylidine aniline N-oxide;N-(naphthylidene)aniline N-oxide; N-(hydroxybenzylidene)aniline N-oxide;and 2,2′-dibenzimidazyl 3,3′-dioxide (indigo N,N-dioxide) for amineN-oxides; and azoxybenzene; phthalazine N-oxide; benzocinnoline N-oxide;and bipyrazinyl N-oxide as N-diazine oxide examples.

N—O Valence Stabilizer #14: Examples of hydrazides, bis(hydrazides), andpoly(hydrazides) (N—O Bidentates and N—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: formic hydrazide; acetic hydrazide;propionic hydrazide; benzoic hydrazide; phthalhydrazide; salicylichydrazide; naphthoic hydrazides; norbornaneacetic hydrazide; nicotinichydrazide; and isonicotinic hydrazide (isoniazid). [Note: hydrazidesprefer complexation with lower oxidation states in metal ions.]

N—O Valence Stabilizer #15: Examples of semicarbazides,bis(semicarbazides), and poly(semicarbazides) (N—O Bidentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: semicarbazide (sc); semicarbazide diacetic acid (sda);1-methylsemicarbazide; 1-ethylsemicarbazide; 1-isopropylsemicarbazide;1-phenylsemicarbazide; 1-benzylsemicarbazide; 1-cyclohexylsemicarbazide;1-norbornylsemicarbazide; 4-methylsemicarbazide; 4-ethylsemicarbazide;4-isopropylsemicarbazide; 4-phenylsemicarbazide; 4-benzylsemicarbazide;4-cyclohexylsemicarbazide; 4-norbornylsemicarbazide; nicotinicsemicarbazide; and isonicotinic semicarbazide. [Note: semicarbazidesprefer complexation with lower oxidation states in metal ions.]

N—O Valence Stabilizer #16: Examples of five-, seven-, or nine-memberedmacrocyclics, macrobicyclics, and macropolycyclics (includingcatapinands, cryptands, cyclidenes, and sepulchrates) wherein allbinding sites are composed of nitrogen (usually amine or imine groups)or oxygen (usually hydroxy, carboxy, or carbonyl groups) and are notcontained in component heterocyclic rings (N—O Tridentates, N—OTetradentates, and N—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: triazadioxacyclodecane ([10]aneO₂N₃);triazadioxacycloundecane ([11]aneO₂N₃); triazadioxacyclododecane([12]aneO₂N₃); triazadioxacyclotridecane ([13]aneO₂N₃);triazadioxacyclotetradecane ([14]aneO₂N₃); andtriazadioxacyclopentadecane ([15]aneO₂N₃).

N—O Valence Stabilizer #17: Examples of five- or seven-memberedmacrocyclics, macrobicyclics, and macropolycyclics (includingcatapinands, cryptands, cyclidenes, and sepulchrates) wherein allbinding sites are composed of nitrogen or oxygen and are contained incomponent heterocyclic rings (N—O Bidentates, N—O Tridentates, N—OTetradentates, or N—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: dipyrantripyridines; difurantripyrroles;tripyrantetrapyridines; and trifurantetrapyrroles.

N—O Valence Stabilizer #18: Examples of five-, seven-, or nine-memberedmacrocyclics, macrobicyclics, and macropolycyclics (includingcatapinands, cryptands, cyclidenes, and sepulchrates) wherein allbinding sites are composed of nitrogen or oxygen and are contained in acombination of heterocyclic rings and amine, imine, hydroxy, carboxy, orcarbonyl groups (N—O Bidentates, N—O Tridentates, N—O Tetradentates, orN—O Hexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:azaoxapentaphyrins; diazadioxapentaphyrins; azaoxapentaphyrins; anddiazadioxapentaphyrins.

S—O Valence Stabilizer #1: Examples of thiobiurets (thioimidodicarbonicdiamides), thioisobiurets, thiobiureas, thiotriurets, thiotriureas,bis(thiobiurets), bis(thioisobiurets), bis(thiobiureas),poly(thiobiurets), poly(thioisobiurets), and poly(thiobiureas) (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: thiobiuret, thioisobiuret, thiobiurea,thiotriuret, thiotriurea, nitrothiobiuret, dinitrothiobiuret,aminothiobiuret, diaminothiobiuret, oxythiobiuret, dioxythiobiuret,cyanothiobiuret, methylthiobiuret, ethylthiobiuret, isopropylthiobiuret,phenylthiobiuret, benzylthiobiuret, cyclohexylthiobiuret,norbornylthiobiuret, adamantylthiobiuret, dimethylthiobiuret,diethylthiobiuret, diisopropylthiobiuret, diphenylthiobiuret,dibenzylthiobiuret, dicyclohexylthiobiuret, dinorbornylthiobiuret,diadamantylthiobiuret' and 3-formamidino thiocarbamides.

S—O Valence Stabilizer #2: Examples of acylthioureas, aroylthioureas,thioacylureas, thioaroylureas, bis(acylthioureas), bis(aroylthioureas),bis(thioacylureas), bis(thioaroylureas), poly(thioacylthioureas),poly(thioaroylthioureas), poly(thioacylureas), and poly(thioaroylureas)(S—O Bidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: thioformylurea, thioacetylurea,thiobenzoylurea, thiocyclohexoylurea, pentafluorothiobenzoylurea,acetylthiourea, benzoylthiourea, and cyclohexoylthiourea.

S—O Valence Stabilizer #3: Examples of thioimidodialdehydes,thiohydrazidodialdehydes (thioacyl hydrazides),bis(thioimidodialdehydes), bis(thiohydrazidodialdehydes),poly(thioimidodialdehydes), and poly(thiohydrazidodialdehydes) (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: thiodiacetamide, thiodipropanamide,thiodibutanamide, thiodibenzamide, and thiodicyclohexamide.

S—O Valence Stabilizer #4: Examples of thioimidodicarbonic acids,thiohydrazidodicarbonic acids, bis(thioimidodicarbonic acids),bis(thiohydrazidodicarbonic acids), poly(thioimidodicarbonic acids),poly(thiohydrazidodicarbonic acids) and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: thioimidodicarbonic acid,thiohydrazidodicarbonic acid, O-phenylthioimidodicarbonic acid,O-benzylthioimidodicarbonic acid, O-cyclohexylthioimidodicarbonic acid,O-norbornylthioimidodicarbonic acid, O,O′-diphenylthioimidodicarbonicacid, O,O′-dibenzylthioimidodicarbonic acid,O,O′-dicyclohexylthioimidodicarbonic acid,O,O′-dinorbornylthioimidodicarbonic acid.

S—O Valence Stabilizer #5: Examples of 1,2-monothioketones(monothiolenes, monothio-alpha-ketonates), 1,2,3-monothioketones,1,2,3-dithioketones, monothiotropolonates, ortho-monothioquinones,bis(1,2-monothioketones), and poly(1,2-monothioketones) (S—O Bidentates,S—O Tridentates, S—O Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: monothiotropolone; 1,2-monothiobenzoquinone(o-monothioquinone); di-tert-butyl-1,2-monothiobenzoquinone;hexafluoro-1,2-monothiobenzoquinone; 1,2-monothionaphthoquinone;9,10-monothiophenanthroquinone; monothiosquaric acid; monothiodelticacid; monothiocroconic acid; and monothiorhodizonic acid.

S—O Valence Stabilizer #6: Examples of trithioperoxydicarbonic diamides,bis(trithioperoxydicarbonic diamides), and poly(trithioperoxydicarbonicdiamides) (S—O Bidentates, S—O Tridentates, S—O Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: trithioperoxydicarbonic diamide;N-phenyltrithioperoxydicarbonic diamide; N-benzyltrithioperoxydicarbonicdiamide; N-cyclohexyltrithioperoxydicarbonic diamide;N-norbornyltrithioperoxydicarbonic diamide;N,N′-diphenyltrithioperoxydicarbonic diamide;N,N′-dibenzyltrithioperoxydicarbonic diamide;N,N′-dicyclohexyltrithioperoxydicarbonic diamide; andN,N′-dinorbornyltrithioperoxydicarbonic diamide.

S—O Valence Stabilizer #7: Examples of dithiodicarbonic acids,bis(dithiodicarbonic acids), poly(dithiodicarbonic acids), andderivatives thereof (S—O Bidentates, S—O Tridentates, S—O Tetradentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: dithiodicarbonic acid,O-phenyldithiodicarbonic acid, O-benzyldithiodicarbonic acid,O-cyclohexyldithiodicarbonic acid, O-norbornyldithiodicarbonic acid,O,O′-diphenyldithiodicarbonic acid, O,O′-dibenzyldithiodicarbonic acid,O,O′-dicyclohexyldithiodicarbonic acid, andO,O′-dinorbornyldithiodicarbonic acid.

S—O Valence Stabilizer #8: Examples of trithioperoxydicarbonic acids,bis(trithioperoxydicarbonic acids), poly(trithioperoxydicarbonic acids),and derivatives thereof (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:trithioperoxydicarbonic acid, O-phenyltrithioperoxydicarbonic acid;O-benzyltrithioperoxydicarbonic acid;O-cyclohexyltrithioperoxydicarbonic acid;O-norbornyltrithioperoxydicarbonic acid;O,O′-diphenyltrithioperoxydicarbonic acid;O,O′-dibenzyltrithioperoxydicarbonic acid;O,O′-dicyclohexyltrithioperoxydicarbonic acid; andO,O′-dinorbornyltrithioperoxydicarbonic acid.

S—O Valence Stabilizer #9: Examples of monothioperoxydiphosphoramides,bis(monothioperoxydiphosphoramides), andpoly(monothioperoxydiphosphoramides) (S—O Bidentates, S—O Tridentates,S—O Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:monothioperoxydiphosphoramide, N-methylmonothioperoxydiphosphoramide,N-isopropylmonothioperoxydiphosphoramide,N-tert-butylmonothioperoxydiphosphoramide,N-phenylmonothioperoxydiphosphoramide,N-pentafluorophenylmonothioperoxydiphosphoramide,N-benzylmonothioperoxydiphosphoramide,N-cyclohexylmonothioperoxydiphosphoramide,N-norbornylmonothioperoxydiphosphoramide,N,N′″-dimethylmonothioperoxydiphosphoramide,N,N′″-diisopropylmonothioperoxydiphosphoramide,N,N′″-di-tert-butylmonothioperoxydiphosphoramide,N,N′″-diphenylmonothioperoxydiphosphoramide,N,N′″-di-pentafluorophenylmonothioperoxydiphosphoramide,N,N′″-dibenzylmonothioperoxydiphosphoramide,N,N′″-dicyclohexylmonothioperoxydiphosphoramide, andN,N′″-dinorbornylmonothioperoxydiphosphoramide.

S—O Valence Stabilizer #10: Examples of monothioperoxydiphosphoricacids, bis(monothioperoxydiphosphoric acids),poly(monothioperoxydiphosphoric acids), and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothioperoxydiphosphoric acid,methylmonothioperoxydiphosphoric acid,isopropylmonothioperoxydiphosphoric acid,tert-butylmonothioperoxydiphosphoric acid,phenylmonothioperoxydiphosphoric acid,pentafluorophenylmonothioperoxydiphosphoric acid,benzylmonothioperoxydiphosphoric acid,cyclohexylmonothioperoxydiphosphoric acid,norbornylmonothioperoxydiphosphoric acid,dimethylmonothioperoxydiphosphoric acid,diisopropylmonothioperoxydiphosphoric acid,di-tert-butylmonothioperoxydiphosphoric acid,diphenylmonothioperoxydiphosphoric acid,di-pentafluorophenylmonothioperoxydiphosphoric acid,dibenzylmonothioperoxydiphosphoric acid,dicyclohexylmonothioperoxydiphosphoric acid, anddinorbornylmonothioperoxydiphosphoric acid.

S—O Valence Stabilizer #11: Examples of monothioimidodiphosphonic acids,monothiohydrazidodiphosphonic acids, bis(monothioimidodiphosphonicacids), bis(monothiohydrazidodiphosphonic acids),poly(monothioimidodiphosphonic acids),poly(monothiohydrazidodiphosphonic acids), and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothioimidodiphosphonic acid,methylmonothioimidodiphosphonic acid, isopropylmonothioimidodiphosphonicacid, tert-butylmonothioimidodiphosphonic acid,phenylmonothioimidodiphosphonic acid,pentafluorophenylmonothioimidodiphosphonic acid,benzylmonothioimidodiphosphonic acid,cyclohexylmonothioimidodiphosphonic acid,norbornylmonothioimidodiphosphonic acid,dimethylmonothioimidodiphosphonic acid,diisopropylmonothioimidodiphosphonic acid,di-tert-butylmonothioimidodiphosphonic acid,diphenylmonothioimidodiphosphonic acid,di-pentafluorophenylmonothioimidodiphosphonic acid,dibenzylmonothioimidodiphosphonic acid,dicyclohexylmonothioimidodiphosphonic acid, anddinorbornylmonothioimidodiphosphonic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S—O Valence Stabilizer #12: Examples of monothioimidodiphosphonamides,monothiohydrazidodiphosphonamides, bis(monothioimidodiphosphonamides),bis(monothiohydrazidodiphosphonamides),poly(monothioimidodiphosphonamides), andpoly(monothiohydrazidodiphosphonamides) (S—O Bidentates, S—OTridentates, S—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: monothioimidodiphosphonamide, N-methylmonothioimidodiphosphonamide,N-isopropylmonothioimidodiphosphonamide,N-tert-butylmonothioimidodiphosphonamide,N-phenylmonothioimidodiphosphonamide,N-pentafluorophenylmonothioimidodiphosphonamide,N-benzylmonothioimidodiphosphonamide,N-cyclohexylmonothioimidodiphosphonamide,N-norbornylmonothioimidodiphosphonamide,N,N′″-dimethylmonothioimidodiphosphonamide,N,N′″-diisopropylmonothioimidodiphosphonamide,N,N′″-di-tert-butylmonothioimidodiphosphonamide,N,N′″-diphenylmonothioimidodiphosphonamide,N,N′″-di-pentafluorophenylmonothioimidodiphosphonamide,N,N′″-dibenzylmonothioimidodiphosphonamide,N,N′″-dicyclohexylmonothioimidodiphosphonamide, andN,N′″-dinorbornylmonothioimidodiphosphonamide. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.]

S—O Valence Stabilizer #13: Examples of dithiodiphosphonamides,bis(dithiodiphosphonamides), and poly(dithiodiphosphonamides) (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiodiphosphonamide,N-methyldithiodiphosphonamide, N-isopropyldithiodiphosphonamide,N-tert-butyldithiodiphosphonamide, N-phenyldithiodiphosphonamide,N-pentafluorophenyldithiodiphosphonamide, N-benzyldithiodiphosphonamide,N-cyclohexyldithiodiphosphonamide, N-norbornyldithiodiphosphonamide,N,N′″-dimethyldithiodiphosphonamide,N,N′″-diisopropyldithiodiphosphonamide,N,N′″-di-tert-butyldithiodiphosphonamide,N,N′″-diphenyldithiodiphosphonamide,N,N′″-di-pentafluorophenyldithiodiphosphonamide,N,N′″-dibenzyldithiodiphosphonamide,N,N′″-dicyclohexyldithiodiphosphonamide, andN,N′″-dinorbornyldithiodiphosphonamide. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S—O Valence Stabilizer #14: Examples of dithiodiphosphonic acids,bis(dithiodiphosphonic acids), poly(dithiodiphosphonic acids), andderivatives thereof (S—O Bidentates, S—O Tridentates, S—O Tetradentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: dithiodiphosphonic acid,methyldithiodiphosphonic acid, isopropyldithiodiphosphonic acid,tert-butyldithiodiphosphonic acid, phenyldithiodiphosphonic acid,pentafluorophenyldithiodiphosphonic acid, benzyldithiodiphosphonic acid,cyclohexyldithiodiphosphonic acid, norbornyldithiodiphosphonic acid,dimethyldithiodiphosphonic acid, diisopropyldiothiodiphosphonic acid,di-tert-butyldithiodiphosphonic acid, diphenyldithiodiphosphonic acid,di-pentafluorophenyldithiodiphosphonic acid, dibenzyldithiodiphosphonicacid, dicyclohexyldithiodiphosphonic acid, anddinorbornyldithiodiphosphoric acid. [Note: the phosphite (P⁺³) valenceof the phosphorus atom makes stabilizization of high valence metal ionsmuch more difficult, though still possible.]

S—O Valence Stabilizer #15: Examples of monothioperoxydiphosphonamides,bis(monothioperoxydiphosphonamides), andpoly(monothioperoxydiphosphonamides) (S—O Bidentates, S—O Tridentates,S—O Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:monothioperoxydiphosphonamide, N-methylmonothioperoxydiphosphonamide,N-isopropylmonothioperoxydiphosphonamide,N-tert-butylmonothioperoxydiphosphonamide,N-phenylmonothioperoxydiphosphonamide,N-pentafluorophenylmonothioperoxydiphosphonamide,N-benzylmonothioperoxydiphosphonamide,N-cyclohexylmonothioperoxydiphosphonamide,N-norbornylmonothioperoxydiphosphonamide,N,N′″-dimethylmonothioperoxydiphosphonamide,N,N′″-diisopropylmonothioperoxydiphosphonamide,N,N′″-di-tert-butylmonothioperoxydiphosphonamide,N,N′″-diphenylmonothioperoxydiphosphonamide,N,N′″-di-pentafluorophenylmonothioperoxydiphosphonamide,N,N′″-dibenzylmonothioperoxydiphosphonamide,N,N′″-dicyclohexylmonothioperoxydiphosphonamide, andN,N′″-dinorbornylmonothioperoxydiphosphonamide. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.)

S—O Valence Stabilizer #16: Examples of monothioperoxydiphosphonicacids, bis(monothioperoxydiphosphonic acids),poly(monothioperoxydiphosphonic acids), and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: monothioperoxydiphosphonic acid,methylmonothioperoxydiphosphonic acid,isopropylmonothioperoxydiphosphonic acid,tert-butylmonothioperoxydiphosphonic acid,phenylmonothioperoxydiphosphonic acid,pentafluorophenylmonothioperoxydiphosphonic acid,benzylmonothioperoxydiphosphonic acid,cyclohexylmonothioperoxydiphosphonic acid,norbornylmonothioperoxydiphosphonic acid,dimethylmonothioperoxydiphosphonic acid,diisopropylmonothioperoxydiphosphonic acid,di-tert-butylmonothioperoxydiphosphonic acid,diphenylmonothioperoxydiphosphonic acid,di-pentafluorophenylmonothioperoxydiphosphonic acid,dibenzylmonothioperoxydiphosphonic acid,dicyclohexylmonothioperoxydiphosphonic acid, anddinorbornylmonothioperoxydiphosphonic acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S—O Valence Stabilizer #17: Examples of monothiophosphoric acids(phosphorothioic acids), bis(monothiophosphoric acids),poly(monothiophosphoric acids), and derivatives thereof (S—O Bidentates,S—O Tridentates, S—O Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: monothiophosphoric acid, O-phenylmonothiophosphoric acid,O-benzylmonothiophosphoric acid, O-cyclohexylmonothiophosphoric acid,O-norbornylmonothiophosphoric acid, O,O-diphenylmonothiophosphoric acid,O,O-dibenzylmonothiophosphoric acid, O,O-dicyclohexylmonothiophosphoricacid, and O,O-dinorbornylmonothiophosphoric acid.

S—O Valence Stabilizer #18: Examples of phosphoro(dithioperoxoic)acids,bis[phosphoro(dithioperoxoic)acids],poly[phosphoro(dithioperoxoic)acids], and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphoro(dithioperoxoic) acid,O-phenylphosphoro(dithioperoxoic)acid, O-benzylphosphoro(dithioperoxoic)acid, O-cyclohexylphosphoro(dithioperoxoic)acid,O-norbornylphosphoro(dithioperoxoic) acid,O,O-diphenylphosphoro(dithioperoxoic)acid,O,O-dibenzylphosphoro(dithioperoxoic) acid,O,O-dicyclohexylphosphoro(dithioperoxoic)acid, andO,O-dinorbornylphosphoro(dithioperoxoic)acid.

S—O Valence Stabilizer #19: Examples of monothiophosphonic Acids(phosphonothioic acids), bis(monothiophosphonic acids),poly(monothiophosphonic acids), and derivatives thereof (S—O Bidentates,S—O Tridentates, S—O Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: monothiophosphonic acid, O-phenylmonothiophosphonic acid,O-benzylmonothiophosphonic acid, O-cyclohexylmonothiophosphonic acid,O-norbornylmonothiophosphonic acid, O,P-diphenylmonothiophosphonic acid,O,P-dibenzylmonothiophosphonic acid, O,P-dicyclohexylmonothiophosphonicacid, and O,P-dinorbornylmonothiophosphonic acid. [Note: the phosphite(P⁺³) valence of the phosphorus atom makes stabilizization of highvalence metal ions much more difficult, though still possible.]

S—O Valence Stabilizer #20: Examples of phosphono(dithioperoxoic)acids,bis[phosphono(dithioperoxoic)acids],poly[phosphono(dithioperoxoic)acids], and derivatives thereof (S—OBidentates, S—O Tridentates, S—O Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphono(dithioperoxoic) acid,O-phenylphosphono(dithioperoxoic)acid, O-benzylphosphono(dithioperoxoic)acid, O-cyclohexylphosphono(dithioperoxoic)acid,O-norbornylphosphono(dithioperoxoic) acid,O,P-diphenylphosphono(dithioperoxoic)acid,O,P-dibenzylphosphono(dithioperoxoic) acid,O,P-dicyclohexylphosphono(dithioperoxoic)acid, andO,P-dinorbornylphosphoro(dithioperoxoic)acid. [Note: the phosphite (P⁺³)valence of the phosphorus atom makes stabilizization of high valencemetal ions much more difficult, though still possible.]

S—O Valence Stabilizer #21: Examples of beta-hydroxythioketones,beta-hydroxythioaldehydes, bis(beta-hydroxythioketones),bis(beta-hydroxythioaldehydes), poly(beta-hydroxythioketones), andpoly(beta-hydroxythioaldehydes) (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:4-hydroxypentan-2-thione; 1,3-diphenyl-3-hydroxypropanethioaldehyde;1,3-dibenzyl-3-hydroxypropanethioaldehyde;1,3-dicyclohexyl-3-hydroxypropanethioaldehyde;1,3-dinorbornyl-3-hydroxypropanethioaldehyde;1,3-di(2-thienyl)-3-hydroxypropanethioaldehyde;1,3-di(2-furyl)-3-hydroxypropanethioaldehyde; o-hydroxythioacetophenone;and beta-hydroxythiobenzophenone.

S—O Valence Stabilizer #22: Examples of beta-mercaptoketones,beta-mercaptoaldehydes, bis(beta-mercaptoketones),bis(beta-mercaptoaldehydes), poly(beta-mercaptoketones), andpoly(beta-mercaptoaldehydes) (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:4-mercaptopentan-2-one; 1,3-diphenyl-3-mercaptopropanal;1,3-dibenzyl-3-mercaptopropanal; 1,3-dicyclohexyl-3-mercaptopropanal;1,3-dinorbornyl-3-mercaptopropanal;1,3-di(2-thienyl)-3-mercaptopropanal;1,3-di(2-furyl)-3-mercaptopropanal; 3-mercapto-1,5-pentanedialdehyde;o-mercaptoacetophenone; 5-mercapto-1,4-naphthoquinone;1-mercaptoacridone; 1-mercaptoanthraquinone;1,8-dimercaptoanthraquinone; and beta-mercaptobenzophenone.

S—O Valence Stabilizer #23: Examples of N-(aminomethylol)thioureas[N-(aminohydroxymethyl)thioureas], bis[N-(aminomethylol)thioureas], andpoly[N-(aminomethylol)thioureas] (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce+4 include, but are not limited to:N′-(aminohydroxymethyl)thiourea;N,N″-dimethyl-N′-(aminohydroxymethyl)thiourea;N,N′-diethyl-N′-(aminohydroxymethyl)thiourea;N,N″-isopropyl-N′-(aminohydroxymethyl)thiourea;N,N″-diphenyl-N′-(aminohydroxymethyl)thiourea;N,N″-dibenzyl-N′-(aminohydroxymethyl)thiourea;N,N″-dicyclohexyl-N′-(aminohydroxymethyl)thiourea; andN,N″-dinorbornyl-N′-(aminohydroxymethyl)thiourea.

S—O Valence Stabilizer #24: Examples of N-(aminomethylthiol)ureas[N-(aminomercaptomethyl)ureas], bis[N-(aminomethylthiol)ureas], andpoly[N-(aminomethylthiol)ureas] (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N′-(aminomercaptomethyl)urea;N,N″-dimethyl-N′-(aminomercaptomethyl)urea;N,N′-diethyl-N′-(aminomercaptomethyl)urea;N,N″-isopropyl-N′-(aminomercaptomethyl)urea;N,N″-diphenyl-N′-(aminomercaptomethyl)urea;N,N″-dibenzyl-N′-(aminomercaptomethyl)urea;N,N″-dicyclohexyl-N′-(aminomercaptomethyl)urea; andN,N″-dinorbornyl-N′-(aminomercaptomethyl)urea.

S—O Valence Stabilizer #25: Examples of monothiooxamides,bis(monothiooxamides), and poly(monothiooxamides) (S—O Bidentates, S—OTridentates, S—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: monothiooxamide, N-methylthiooxamide; N-ethylthiooxamide;N-isopropylthiooxamide; N-phenylthiooxamide; N-benzylthiooxamide;N-cyclohexylthiooxamide; N-norbornylthiooxamide;N,N′-dimethylthiooxamide; N,N′-diethylthiooxamide;N,N′-diisopropylthiooxamide; N,N′-diphenylthiooxamide;N,N′-dibenzylthiooxamide; N,N′-dicyclohexylthiooxamide; andN,N′-dinorbornylthiooxamide.

S—O Valence Stabilizer #26: Examples of beta-mercapto carboxylic acids,bis(beta-mercapto carboxylic acids), poly(beta-mercapto carboxylicacids), and derivatives thereof (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: methyl3-mercaptopropanoate; methyl 3-mercaptobutanoate; ethyl3-mercaptobutanoate; phenyl 3-mercaptobutanoate; cyclohexyl3-mercaptobutanoate; norbornyl 3-mercaptobutanoate; methylbeta-mercaptohydrocinnamate; ethyl beta-mercaptohydrocinnamate; phenylbeta-mercaptohydrocinnamate; methyl o-mercaptobenzoate; ethylo-mercaptobenzoate; phenyl o-mercaptobenzoate; cyclohexylo-mercaptobenzoate; (2-benzothiazolylthio)succinic acid (mtbs);norbornyl o-mercaptobenzoate; and 3-[(benzothiazol-2-yl)thio]propionicacid.

S—O Valence Stabilizer #27: Examples of beta-mercapto thiocarboxylicacids, bis(beta-mercapto thiocarboxylic acids), poly(beta-mercaptothiocarboxylic acids), and derivatives thereof (S—O Bidentates, S—OTridentates, S—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: methyl 3-mercaptothiobutanoate; ethyl 3-mercaptothiobutanoate;phenyl 3-mercaptothiobutanoate; cyclohexyl 3-mercaptothiobutanoate;norbornyl 3-mercaptothiobutanoate; methyl beta-mercaptothiocinnamate;ethyl beta-mercaptothiocinnamate; phenyl beta-mercaptothiocinnamate;methyl o-mercaptothiobenzoate; ethyl o-mercaptothiobenzoate; phenylo-mercaptothiobenzoate; cyclohexyl o-mercaptothiobenzoate; norbornylo-mercaptothiobenzoate; and (dialkylthio)oxoethyl alkyl(aryl)disulfides.

S—O Valence Stabilizer #28: Examples of beta-hydroxy thiocarboxylicacids, bis(beta-hydroxy thiocarboxylic acids), poly(beta-hydroxythiocarboxylic acids), and derivatives thereof (S—O Bidentates, S—OTridentates, S—O Tetradentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: methyl 3-hydroxythiobutanoate; ethyl 3-hydroxythiobutanoate; phenyl3-hydroxythiobutanoate; cyclohexyl 3-hydroxythiobutanoate; norbornyl3-hydroxythiobutanoate; methyl beta-hydroxythiocinnamate; ethylbeta-hydroxythiocinnamate; phenyl beta-hydroxythiocinnamate; methylo-hydroxythiobenzoate; ethyl o-hydroxythiobenzoate; phenylo-hydroxythiobenzoate; cyclohexyl o-hydroxythiobenzoate; and norbornylo-hydroxythiobenzoate.

S—O Valence Stabilizer #29: Examples of beta-mercapto carboxamides,bis(beta-mercapto carboxamides), poly(beta-mercapto carboxamides), andderivatives thereof (S—O Bidentates, S—O Tridentates, S—O Tetradentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: N-methyl 3-mercaptobutanamide;N-ethyl 3-mercaptobutanamide; N-phenyl 3-mercaptobutanamide;N-cyclohexyl 3-mercaptobutanamide; N-norbornyl 3-mercaptobutanamide;N-methyl o-mercaptobenzamide; N-ethyl o-mercaptobenzamide; N-phenylo-mercaptobenzamide; N-cyclohexyl o-mercaptobenzamide; and N-norbornylo-mercaptobenzamide.

S—O Valence Stabilizer #30: Examples of S-alkylthiocarboxylic Acids,S-arylthiocarboxylic Acids, and S,S-thiobiscarboxylic Acids (S—OBidentates and S—O Tridentates) that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: (methylthio)acetic acid; (methylthio)benzoic acid;(methylthio)nicotinic acid; (methylthio)napthoic acid;(phenylthio)acetic acid; (phenylthio)benzoic acid; (phenylthio)naphthoicacid; (norbornylthio)acetic acid; (norbornylthio)benzoic acid;(norbornylthio)napthoic acid; thiobisacetic acid; thiobisbenzoic acid;and thiobisnapthoic acid.

S—O Valence Stabilizer #31: Examples of S-alkyldisulfidocarboxylicacids, S-aryldisulfidocarboxylic acids, and S,S′-disulfidobiscarboxylicacids (S—O Bidentates and S—O Tridentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: (methyldisulfido)acetic acid; (methyldisulfido)benzoicacid; (methyldisulfido)nicotinic acid; (methyldisulfido)napthoic acid;(phenyldisulfido)acetic acid; (phenyldisulfido)benzoic acid;(phenyldisulfido)naphthoic acid; (norbornyldisulfido)acetic acid;(norbornyldisulfido)benzoic acid; (norbornyldisulfido)napthoic acid;S,S′-disulfidobisacetic acid; S,S′-disulfidobisbenzoic acid; andS,S′-disulfidobisnapthoic acid.

S—O Valence Stabilizer #32: Examples of monothiomonocarboxylic acids,dithiodicarboxylic acids, bis(monothiomonocarboxylic acids),bis(dithiodicarboxylic acids), poly(monothiomonocarboxylic acids),poly(dithiodicarboxylic acids), and derivatives thereof (S—O Bidentatesand S—O Tetradentates) that meet the requirements for use as “narrowband” valence stabilizers for Ce⁺⁴ include, but are not limited to:thioacetic acid; thiopropionic acid; thiobenzoic acid; thiophenylaceticacid; thiocyclohexanoic acid; thiofuroic acid; thionaphthoic acid;phenyl thioacetate; phenyl thiopropionate; phenyl thiobenzoate; phenylthiocyclohexanoate; phenyl thiofuroate; phenyl thionaphthoate;dithiooxalic acid (dto); monothiooxalic acid (mtox); dithiomalonic acid;dithiosuccinic acid; diphenyl dithiooxalate; diphenyl dithiomalonate;and diphenyl dithiosuccinate.

S—O Valence Stabilizer #33: Examples of monothiocarbonates andbis(monothiocarbonates) (S—O Bidentates and S—O Tetradentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: S,O-diethyldithiocarbonate;S,O-diisopropyldithiocarbonate; S,O-diphenyldithiocarbonate;S,O-dibenzyldithiocarbonate; S,O-dicyclohexyldithiocarbonate; andS,O-dinorbornyldithiocarbonate.

S—O Valence Stabilizer #34: Examples of monothiocarbazates(monothiocarbazides), bis(monothiocarbazates), andpoly(monothiocarbazates) (S—O Bidentates, S—O Tridentates, and S—OTetradentates; or possibly N—S Bidentates, N—S Tridentates, and N—STetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:N,N′-dimethylmonothiocarbazate;N,N′-di(trifluoromethyl)monothiocarbazate;N,N′-diethylmonothiocarbazate; N,N′-diphenylmonothiocarbazate;N,N′-dibenzylmonothiocarbazate;N,N′-di(pentafluorophenyl)monothiocarbazate;N,N′-dicyclohexylmonothiocarbazate; andN,N′-dinorbornylmonothiocarbazate.

S—O Valence Stabilizer #35: Examples of mercapto alcohols andsilylmercaptoalcohols, bis(mercapto alcohols and silylmercaptoalcohols),and poly(mercapto alcohols and silylmercaptoalcohols) (S—O Bidentates,S—O Tridentates, S—O Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-mercaptoethanol (mel); 3-mercaptopropanol (mpl);2-mercaptophenol; 2-mercaptocyclohexanol; 3-mercapto-2-norborneol;2-mercaptopyridine 1-oxide; 1,4-thioxane; thiodialkanols;2-(trimethoxysilyl)-1-ethanethiol (tmset);3-(trimethoxysilylfil-propanethiol (tmspt); o-hydroxythiophenols;o-(O-hydroxyalkyl(aryl))thiophenols; and o-(S-thioalkyl(aryl))phenols.

S—O Valence Stabilizer #36: Examples of monothiocarbimates,bis(monothiocarbimates), and poly(monothiocarbimates) (S—O Bidentates,S—O Tridentates, and S—O Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: methylmonothiocarbimate; trifluoromethylmonothiocarbimate;ethylmonothiocarbimate; propylmonothiocarbimate;isopropylmonothiocarbimate; butylmonothiocarbimate;tertbutylmonothiocarbimate; cyanomonothiocarbimate;cyanamidomonothiocarbimate; azidomonothiocarbimate;phenylmonothiocarbimate; pentafluorophenylmonothiocarbimate;benzylmonothiocarbimate; naphthylmonothiocarbimate;cyclohexylmonothiocarbimate; norbornylmonothiocarbimate; andadamantylmonothiocarbimate. [Note: carbimates tend to stabilize loweroxidation states in metal ions.]

S—O Valence Stabilizer #37: Examples of alkyl- and aryl-monothioboratesand bis(monothioborates) (S—O Bidentates and S—O Tetradentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: O,O′-diethyl monothioborate;O,O′-diisopropyl monothioborate; O,O′-diphenyl monothioborate;O,O′-dibenzyl monothioborate; O,O′-dicyclohexyl monothioborate; andO,O′-dinorbornyl monothioborate.

S—O Valence Stabilizer #38: Examples of alkyl- andaryl-monothioboronates and bis(monothioboronates) (S—O Bidentates andS—O Tetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: diethylmonothioboronate; diisopropyl monothioboronate; diphenylmonothioboronate; dibenzyl monothioboronate; dicyclohexylmonothioboronate; and dinorbornyl monothioboronate. [Note: boronatestend to stabilize lower oxidation states in metal ions.]

S—O Valence Stabilizer #39: Examples of monothioarsonic acids(arsonothioic acids), bis(monothioarsonic acids), poly(monothioarsonicacids), and derivatives thereof (S—O Bidentates, S—O Tridentates, S—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:monothioarsonic acid, O-phenylmonothioarsonic acid,O-benzylmonothioarsonic acid, O-cyclohexylmonothioarsonic acid,O-norbornylmonothioarsonic acid, O,O-diphenylmonothioarsonic acid,O,O-dibenzylmonothioarsonic acid, O,O-dicyclohexylmonothioarsonic acid,and O,O-dinorbornylmonothioarsonic acid.

S—O Valence Stabilizer #40: Examples of heterocyclic rings containingone or two sulfur atoms and having at least one additional oxygen atombinding site not in a ring (S—O Bidentates, S—O Tridentates, S—OTetradentates, or S—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-thiopheneethanol (2-(2-thienyl)ethanol);2-propionylthiophene (1-(2-thienyl)-1-propanone);N,N′-thiobisphthalimide; 1,1′-thiocarbonyldi-2-pyridone;2-thiopheneacetic acid; 2-thiophenecarboxaldehyde;2-thiophenecarboxamide; 2-thiophenecarboxylic acid;2,5-thiophenedicarboxaldehyde; 2,5-thiophenedicarboxylic acid;2-thiophenemethanol; 2-thiophenone; thiotetronic acid; alky](aryl)2-thienyl ketones; dithienyl ketone; 1,3-dithiane-2-carboxylic acid; and1,3-dithiolane-2-carboxylic acid.

S—O Valence Stabilizer #41: Examples of heterocyclic rings containingone or two oxygen atoms and having at least one additional sulfur atombinding site not in a ring (S—O Bidentates, S—O Tridentates, S—OTetradentates, or S—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-furanethanethiol (2-(2-furyl)ethanethiol);1-(2-furyl-1-propanethione); 2-furanthioacetic acid;2-furanthiocarboxaldehyde; 2-furanthiocarboxamide; 2-furanthiocarboxylicacid; 2,5-furandithiocarboxaldehyde; 2,5-furandithiocarboxylic acid;2-furanmethanethiol; 2-furanthione; furfuryl disulfide; furfurylmercaptan; furfuryl sulfide; and furfuryl methyl disulfide.

S—O Valence Stabilizer #42: Examples of heterocyclic rings containingone or two sulfur atoms and having at least one additional oxygen atombinding site in a separate ring (S—O Bidentates, S—O Tridentates, S—OTetradentates, or S—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-(2-furyl)thiophene; 2,5-(2-furyl)thiophene;2-(2-furyl)thiopyran; and 2,5-(2-furyl)thiopyran.

S—O Valence Stabilizer #43: Examples of two-, three-, four-, five-,six-, seven-, eight-, nine-, and ten-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofsulfur (usually thiol, mercapto, or thiocarbonyl groups) or oxygen(hydroxy, carboxy, or carbonyl groups) and are not contained incomponent heterocyclic rings (S—O Bidentates, S—O Tridentates, S—OTetradentates, and S—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: thiaoxacyclobutane ([4]aneOS); thiaoxacyclopentane([5]aneOS); thiaoxacyclohexane ([6]aneOS); thiaoxacycloheptane([7]aneOS); thiaoxacyclooctane ([8]aneOS); thiaoxacyclobutene([4]eneOS); thiaoxacyclopentene ([5]eneOS); thiaoxacyclohexene([6]eneOS); thiaoxacycloheptene ([7]eneOS); thiaoxacyclooctene([8]eneOS); dithiaoxacyclohexane ([6]aneOS₂); dithiaoxacycloheptane([7]aneOS₂); dithiaoxacyclooctane ([8]aneOS₂); dithiaoxacyclononane([9]aneOS₂); dithiaoxacyclodecane ([10]aneOS₂); dithiaoxacycloundecane([11]aneOS₂); dithiaoxacyclododecane ([12]aneOS₂); dithiaoxacyclohexene([6]eneOS₂); dithiaoxacycloheptene ([7]eneOS₂); dithiaoxacyclooctene([8]eneOS₂); dithiaoxacyclononene ([9]eneOS₂); dithiaoxacyclodecene([10]eneOS₂); dithiaoxacycloundecene ([11]eneOS₂);dithiaoxacyclododecene ([12]eneOS₂); dithiadioxacyclooctane([8]aneO₂S₂); dithiadioxacyclononane ([9]aneO₂S₂);dithiadioxacyclodecane ([10]aneO₂S₂); dithiadioxacycloundecane([11]aneO₂S₂); dithiadioxacyclododecane ([12]aneO₂S₂);dithiadioxacyclotridecane ([13]aneO₂S₂); dithiadioxacyclotetradecane([14]aneO₂S₂); dithiadioxacyclopentadecane ([15]aneO₂S₂);dithiadioxacyclohexadecane ([16]aneO₂S₂); dithiadioxacycloheptadecane([17]aneO₂S₂); dithiadioxacyclooctadecane ([18]aneO₂S₂);dithiadioxacyclononadecane ([19]aneO₂S₂); dithiadioxacycloeicosane([20]aneO₂S₂); dithiadioxacyclooctadiene ([8]dieneO₂S₂);dithiadioxacyclononadiene ([9]dieneO₂S₂); dithiadioxacyclodecadiene([10]dieneO₂S₂); dithiadioxacycloundecadiene ([11]dieneO₂S₂);dithiadioxacyclododecadiene ([12]dieneO₂S₂);dithiadioxacyclotridecadiene ([13]dieneO₂S₂);dithiadioxacyclotetradecadiene ([14]dieneO₂S₂);dithiadioxacyclopentadecadiene ([15]dieneO₂S₂);dithiadioxacyclohexadecadiene ([16]dieneO₂S₂);dithiadioxacycloheptadecadiene ([17]dieneO₂S₂);dithiadioxacyclooctadecadiene ([18]dieneO₂S₂);dithiadioxacyclononadecadiene ([19]dieneO₂S₂); anddithiadioxacycloeicosadiene ([20]dieneO₂S₂).

S—O Valence Stabilizer #44: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of sulfur or oxygenand are contained in component heterocyclic rings (S—O Tridentates, S—OTetradentates, or S—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: difurandithiophenes; difurantrithiophenes;trifurantrithiophenes; and tetrafurantetrathiophenes.

S—O Valence Stabilizer #45: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of sulfur or oxygenand are contained in a combination of heterocyclic rings and thiol,mercapto, thiocarbonyl, hydroxy, carboxy, and carbonyl groups (S—OTridentates, S—O Tetradentates, or S—O Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dithiadifurandithiophenes;tetrathiadifurandithiophenes; trithiatrifurantrithiophenes;trithiatrifurantrithiophenes; tetrathiatetrafurantetrathiophenes; andoctathiatetrafurantetrathiophenes.

S—O Valence Stabilizer #46: Examples of sulfoxides that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dimethylsulfoxide (DMSO);diethylsulfoxide; diphenylsulfoxide; and tetrahydrothiophene oxide.

S—O Valence Stabilizer #47: Examples of sulfones that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dimethyl sulfone; diethyl sulfone; anddiphenyl sulfone.

S—O Valence Stabilizer #48: Examples of sulfur dioxide ligands that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: sulfur dioxide (—SO₂) ligands. [Note:sulfur dioxide is a reducing agent, and complexed metal ions thereforetend to prefer lower oxidation states.]

N—P Valence Stabilizer #1: Examples of aminoaryl phosphines andiminoaryl phosphines (N—P Bidentates, N—P Tridentates, and N—PTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:tri(2-aminophenyl)phosphine; tri(2-aminophenyl)phosphine oxide; andtri(2-aminophenyl)phosphine sulfide.

N—P Valence Stabilizer #2: Examples of heterocyclic rings containingone, two, three, or four nitrogen atoms and having at least oneadditional phosphorus atom binding site not in a ring (N—P Bidentates,N—P Tridentates, N—P Tetradentates, or N—P Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: tri(2-imidazolyl)phosphine;tri(2-pyrrolyl)phosphine; tri(2-pyridyl)phosphine;tri(2-imidazolyl)phosphine oxide; tri(2-pyrrolyl)phosphine oxide;tri(2-pyridyl)phosphine oxide; tri(2-imidazolyl)phosphine sulfide;tri(2-pyrrolyl)phosphine sulfide; and tri(2-pyridyl)phosphine sulfide.

N—P Valence Stabilizer #3: Examples of heterocyclic rings containingone, two, or three phosphorus atoms and having at least one additionalnitrogen atom binding site not in a ring (N—P Bidentates, N—PTridentates, N—P Tetradentates, or N—P Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-aminophosphole; 2,5-diaminophosphole;2-(aminomethyl)phosphole; 2,5-di(aminomethyl)phosphole;2-aminophosphorin; 2,6-diaminophosphorin; 2-(aminomethyl)phosphorin;2,6-di(aminomethyl)phosphorin; triaminocyclotriphosphazenes; andhexaminocyclotriphosphazenes.

N—P Valence Stabilizer #4: Examples of heterocyclic rings containingone, two, three, or four nitrogen atoms and having at least oneadditional phosphorus atom binding site in a separate ring (N—PBidentates, N—P Tridentates, N—P Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2-(2-pyrrolyl)phosphole;2,5-di(2-pyrrolyl)phosphole; 2-(2-pyridyl)phosphorin; and2,6-(2-pyridyl)phosphorin.

N—P Valence Stabilizer #5: Examples of two-, three-, four-, five-, six-,seven-, eight-, nine-, and ten-membered macrocyclics, macrobicyclics,and macropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of nitrogen(usually amine or imine groups) or phosphorus and are not contained incomponent heterocyclic rings (N—P Bidentates, N—P Tridentates, N—PTetradentates, and N—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: cyclobiphosphazenes; cyclotriphosphazenes;cyclotetraphosphazenes; cyclopentaphosphazenes; cyclohexaphosphazenes;diphosphatetraazacyclooctatetraenes; diphospha-s-triazines; andphospha-s-triazines.

N—P Valence Stabilizer #6: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of nitrogen orphosphorus and are contained in component heterocyclic rings (N—PBidentates, N—P Tridentates, N—P Tetradentates, or N—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: diphospholedipyrroles;diphosphorindipyridines; triphospholetripyrroles;triphosphorintripyridines; tetraphospholetetrapyrroles; andtetraphosphorintetrapyridines.

N—P Valence Stabilizer #7: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of nitrogen orphosphorus and are contained in a combination of heterocyclic rings andamine, imine, and phosphine groups (N—P Bidentates, N—P Tridentates, N—PTetradentates, or N—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: azaphosphatetraphyrins; diazadiphosphatetraphyrins;azaphosphahexaphyrins; diazadiphosphahexaphyrins;triazatriphosphahexaphyrins; and apholate.

S—P Valence Stabilizer #1: Examples of thioaryl phosphines (S—PBidentates, S—P Tridentates, S—P Tetradentates, and S—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:tri(2-mercaptophenyl)phosphine; tri(2-mercaptophenyl)phosphine oxide;and tri(2-mercaptophenyl)phosphine sulfide.

S—P Valence Stabilizer #2: Examples of heterocyclic rings containing oneor two sulfur atoms and having at least one additional phosphorus atombinding site not in a ring (S—P Bidentates, S—P Tridentates, S—PTetradentates, or S—P Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tri(2-thiophene)phosphine; tri(2-thiopyran)phosphine;tri(2-thiophene)phosphine oxide; tri(2-thiopyran)phosphine oxide;tri(2-thiophene)phosphine sulfide; and tri(2-thiopyran)phosphinesulfide.

S—P Valence Stabilizer #3: Examples of heterocyclic rings containingone, two, or three phosphorus atoms and having at least one additionalsulfur atom binding site not in a ring (S—P Bidentates, S—P Tridentates,S—P Tetradentates, or S—P Hexadentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-mercaptophosphole; 2,5-dimercaptophosphole;2-(mercaptomethyl)phosphole; 2,5-di(mercaptomethyl)phosphole;2-mercaptophosphorin; 2,6-dimercaptophosphorin;2-(mercaptomethyl)phosphorin; and 2,6-di(mercaptomethyl)phosphorin.

S—P Valence Stabilizer #4: Examples of heterocyclic rings containing oneor two sulfur atoms and having at least one additional phosphorus atombinding site in a separate ring (S—P Bidentates, S—P Tridentates, S—PTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:2-(2-thienyl)phosphole; 2,5-di(2-thienyl)phosphole;2-(2-thienyl)phosphorin; and 2,6-(2-thienyl)phosphorin.

S—P Valence Stabilizer #5: Examples of two-, three-, four-, five-, six-,seven-, eight-, nine-, and ten-membered macrocyclics, macrobicyclics,and macropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of sulfur (usuallythiol, mercapto, or thiocarbonyl groups) or phosphorus and are notcontained in component heterocyclic rings (S—P Bidentates, S—PTridentates, S—P Tetradentates, and S—P Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphathiacyclobutane ([4]anePS);phosphathiacyclopentane ([5]anePS); phosphathiacyclohexane ([6]anePS);phosphathiacycloheptane ([7]anePS); phosphathiacyclooctane ([8]anePS);diphosphathiacyclohexane ([6]aneSP₂); diphosphathiacycloheptane([7]aneSP₂); diphosphathiacyclooctane ([8]aneSP₂);diphosphathiacyclononane ([9]aneSP2); diphosphathiacyclodecane([10]aneSP₂); diphosphathiacycloundecane ([11]aneSP₂);diphosphathiacyclododecane ([12]aneSP₂); diphosphadithiacyclooctane([8]aneS₂P₂); diphosphadithiacyclononane ([9]aneS₂P₂);diphosphadithiacyclodecane ([10]aneS₂P₂); diphosphadithiacycloundecane([11]aneS₂P₂); diphosphadithiacyclododecane ([12]aneS₂P₂);diphosphadithiacyclotridecane ([13]aneS₂P₂);diphosphadithiacyclotetradecane ([14]aneS₂P₂);diphosphadithiacyclopentadecane ([15]aneS₂P₂);diphosphadithiacyclohexadecane ([16]aneS₂P₂);diphosphadithiacycloheptadecane ([17]aneS₂P2);diphosphadithiacyclooctadecane ([18]aneS₂P₂);diphosphadithiacyclononadecane ([19]aneS₂P₂);diphosphadithiacycloeicosane ([20]aneS₂P₂).

S—P Valence Stabilizer #6: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of sulfur orphosphorus and are contained in component heterocyclic rings (S—PBidentates, S—P Tridentates, S—P Tetradentates, or S—P Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: diphospholedithiophenes;diphosphorindithiopyrans; triphospholetrithiophenes;triphosphorintrithiopyrans; tetraphospholetetrathiophenes; andtetraphosphorintetrathiopyrans.

S—P Valence Stabilizer #7: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of sulfur orphosphorus and are contained in a combination of heterocyclic rings andthiol, mercapto, thiocarbonyl, and phosphine groups (S—P Bidentates, S—PTridentates, S—P Tetradentates, or S—P Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: thiaphosphatetraphyrins;dithiadiphosphatetraphyrins; thiaphosphahexaphyrins;dithiadiphosphahexaphyrins; and trithiatriphosphahexaphyrins.

P—O Valence Stabilizer #1: Examples of hydroxyaryl phosphines (P—OBidentates, P—O Tridentates, P—O Tetradentates, and P—O Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: tri(2-hydroxyphenyl)phosphine;tri(2-hydroxyphenyl)phosphine oxide; and tri(2-hydroxyphenyl)phosphinesulfide.

P—O Valence Stabilizer #2: Examples of heterocyclic rings containing oneor two oxygen atoms and having at least one additional phosphorus atombinding site not in a ring (P—O Bidentates, P—O Tridentates, P—OTetradentates, or P—O Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tri(2-furan)phosphine; tri(2-pyran)phosphine;tri(2-furan)phosphine oxide; tri(2-pyran)phosphine oxide;tri(2-furan)phosphine sulfide; and tri(2-pyran)phosphine sulfide.

P—O Valence Stabilizer #3: Examples of heterocyclic rings containingone, two, or three phosphorus atoms and having at least one additionaloxygen atom binding site not in a ring (P—O Bidentates, P—O Tridentates,P—O Tetradentates, or P—O Hexadentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2-hydroxyphosphole; 2,5-dihydroxyphosphole;2-(hydroxymethyl)phosphole; 2,5-di(hydroxymethyl)phosphole;2-hydroxyphosphorin; 2,6-dihydroxyphosphorin;2-(hydroxymethyl)phosphorin; and 2,6-di(hydroxymethyl)phosphorin.

P—O Valence Stabilizer #4: Examples of heterocyclic rings containing oneor two oxygen atoms and having at least one additional phosphorus atombinding site in a separate ring (P—O Bidentates, P—O Tridentates, P—OTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:2-(2-furyl)phosphole; 2,5-di(2-furyl)phosphole; 2-(2-furyl)phosphorin;and 2,6-(2-furyl)phosphorin.

P—O Valence Stabilizer #5: Examples of two-, three-, four-, five-, six-,seven-, eight-, nine-, and ten-membered macrocyclics, macrobicyclics,and macropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of oxygen (usuallyhydroxy, carboxy, or carbonyl groups) or phosphorus and are notcontained in component heterocyclic rings (P—O Bidentates, P—OTridentates, P—O Tetradentates, and P—O Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: phosphaoxacyclobutane ([4]anePO);phosphaoxacyclopentane ([5]anePO); phosphaoxacyclohexane ([6]anePO);phosphaoxacycloheptane ([7]anePO); phosphaoxacyclooctane ([8]anePO);diphosphaoxacyclohexane ([6]aneOP₂); diphosphaoxacycloheptane([7]aneOP₂); diphosphaoxacyclooctane ([8]aneOP₂);diphosphaoxacyclononane ([9]aneOP₂); diphosphaoxacyclodecane([10]aneOP2); diphosphaoxacycloundecane ([11]aneOP₂);diphosphaoxacyclododecane ([12]aneOP₂); diphosphadioxacyclooctane([8]aneO₂P₂); diphosphadioxacyclononane ([9]aneO₂P₂);diphosphadioxacyclodecane ([10]aneO₂P₂); diphosphadioxacycloundecane([11]aneO₂P₂); diphosphadioxacyclododecane ([12]aneO₂P₂);diphosphadioxacyclotridecane ([13]aneO₂P₂);diphosphadioxacyclotetradecane ([14]aneO₂P₂);diphosphadioxacyclopentadecane ([15]aneO₂P₂);diphosphadioxacyclohexadecane ([16]aneO₂P₂);diphosphadioxacycloheptadecane ([17]aneO₂P₂);diphosphadioxacyclooctadecane ([18]aneO₂P₂);diphosphadioxacyclononadecane ([19]aneO₂P₂); diphosphadioxacycloeicosane([20]aneO₂P₂); and dioxaphospholane.

P—O Valence Stabilizer #6: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of oxygen orphosphorus and are contained in component heterocyclic rings (P—OBidentates, P—O Tridentates, P—O Tetradentates, or P—O Hexadentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: diphospholedifurans;diphosphorindipyrans; triphospholetrifurans; triphosphorintripyrans;tetraphospholetetrafurans; and tetraphosphorintetrapyrans.

P—O Valence Stabilizer #7: Examples of four-, five-, six-, seven-,eight-, nine-, or ten-membered macrocyclics, macrobicyclics, andmacropolycyclics (including catapinands, cryptands, cyclidenes, andsepulchrates) wherein all binding sites are composed of oxygen orphosphorus and are contained in a combination of heterocyclic rings andhydroxy, carboxy, carbonyl, and phosphine groups (P—O Bidentates, P—OTridentates, P—O Tetradentates, or P—O Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: oxaphosphatetraphyrins;dioxadiphosphatetraphyrins; oxaphosphahexaphyrins;dioxadiphosphahexaphyrins; and trioxatriphosphahexaphyrins.

As Valence Stabilizer #1: Examples of monoarsines (As Monodentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: arsine, triphenylarsine,ticyclohexylarsine, methyldiphenylarsine, ethyldiphenylarsine,arsinonorbornane, and arsinoadamantane.

As Valence Stabilizer #2: Examples of diarsines (As Monodentates orAs—As Bidentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:bis(diphenylarsino)methane, bis(diphenylarsino)ethane,bis(diphenylarsino)propane, bis(diphenylarsino)butane,bis(diphenylarsino)pentane, 1,2-diarsinobenzene,cyclohexane-1,2-diarsine, 1,2-bis(phenylbutylarsino)ethane,o-phenylenebis(methylphenylarsine) and o-phenylenebis(dimethylarsine)(diars). [Note: the aryl derivatives are air-stable, whereas the alkylderivatives are air-sensitive and therefore unsuitable for theseapplications.]

As Valence Stabilizer #3: Examples of triarsines (As—As Bidentates, orAs—As Tridentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:1,1,5,9,9-pentaphenyl-1,5,9-triarsanonane,3-methyl-3-(As,As-dimethyl)arsinomethyl-1,1,5,5-tetraphenyl-1,5-diarsapentane,As,As-[o-(As-dimethyl)arsinodiphenyl]-(As-phenyl)arsine,As,As-[o-(As-diphenyl)arsinodiphenyl]-(As-phenyl)arsine,hexahydro-2,4,6-trimethyl-1,3,5-triarsinazine. [Note: the arylderivatives are air-stable, whereas the alkyl derivatives areair-sensitive and therefore unsuitable for these applications.]

As Valence Stabilizer #4: Examples of tetraarsines (As—As Bidentates,As—As Tridentates, or As—As Tetradentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to:3,3-(As-diphenyl)arsinomethyl-1,1,5,5-tetraphenyl-1,5-diarsapentane.[Note: the aryl derivatives are air-stable, whereas the alkylderivatives are air-sensitive and therefore unsuitable for theseapplications.]

As Valence Stabilizer #5: Examples of pentaarsines (As—As Bidentates,As—As Tridentates, or As—As Tetradentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to:4-[2-(As-diphenyl)arsinoethyl]-1,1,7,10,10-pentaphenyl-1,4,7,10-tetraarsadecane.[Note: The aryl derivatives are air-stable, whereas the alkylderivatives are air-sensitive and therefore unsuitable for theseapplications.]

As Valence Stabilizer #6: Examples of hexaarsines (As—As Bidentates,As—As Tridentates, As—As Tetradentates, or As—As Hexadentates) that meetthe requirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to:o-phenylenebis[di-3-(As-diphenyl)arsinopropylarsine]. [Note: the arylderivatives are air-stable, whereas the alkyl derivatives areair-sensitive and therefore unsuitable for these applications.]

As Valence Stabilizer #7: Examples of 5-membered heterocyclic ringscontaining one arsenic atom (As Monodentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: arsole, azarsole, diazarsole, benzarsole, benzazarsole,dibenzarsole, naphtharsole, naphthazarsole.

As Valence Stabilizer #8: Examples of 6-membered heterocyclic ringscontaining one arsenic atom (As Monodentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: arsenin, azarsenin, diazarsenin, benzarsenin,benzazarsenin, dibenzarsenin, naphtharsenin, and naphthazarsenin.

As Valence Stabilizer #9: Examples of 5-membered heterocyclic ringscontaining one arsenic atom and having at least one additional arsenicatom binding site not contained in a ring (As Monodentates, As—AsBidentates, As—As Tridentates, As—As Tetradentates, or As—AsHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:2-(As-phenylarsino)arsole; 2,5-(As-phenylarsino)arsole;2-(As-phenylarsino)benzarsole; 7-(As-phenylarsino)benzarsole; and1,8-(As-phenylarsino)dibenzarsole.

As Valence Stabilizer #10: Examples of 6-membered heterocyclic ringscontaining one arsenic atom and having at least one additional arsenicatom binding site not contained in a ring (As Monodentates, As—AsBidentates, As—As Tridentates, As—As Tetradentates, or As—AsHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:2-(As-phenylarsino)arsenin; 2,5-(As-phenylarsino)arsenin;2-(As-phenylarsino)benzarsenin; 7-(As-phenylarsino)benzarsenin; and1,9-(As-phenylarsino)dibenzarsenin.

As Valence Stabilizer #11: Examples of 5-membered heterocyclic ringscontaining one arsenic atom and having at least one additional arsenicatom binding site contained in a ring (As Monodentates, As—AsBidentates, As—As Tridentates, As—As Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-biarsole; 2,2′,2″-triarsole; and2,2′-bibenzarsole.

As Valence Stabilizer #12: Examples of 6-membered heterocyclic ringscontaining one arsenic atom and having at least one additional arsenicatom binding site contained in a ring (As Monodentates, As—AsBidentates, As—As Tridentates, As—As Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-biarsenin; 2,2′,2″-triarsenin;2,2′,2′,2′″-tetraarsenin; 2,2′-bibenzarsenin; and 8,8′-bibenzarsenin.

As Valence Stabilizer #13a: Examples of two-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein both binding sites are composed ofarsenic and are not contained in component heterocyclic rings (As—AsBidentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to:As,As-diphenyldiarsacyclobutane ([4]aneAs₂);As,As-diphenyldiarsacyclopentane ([5]aneAs₂);As,As-diphenyldiarsacyclohexane ([6]aneAs₂);As,As-diphenyldiarsacycloheptane ([7]aneAs₂);As,As-diphenyldiarsacyclooctane ([8]aneAs₂);As,As-diphenyldiarsacyclobutene ([4]eneAs₂);As,As-diphenyldiarsacyclopentene ([5]eneAs₂);As,As-diphenyldiarsacyclohexene ([6]eneAs₂);As,As-diphenyldiarsacycloheptene ([7]eneAs₂); andAs,As-diphenyldiarsacyclooctene ([8]eneAs₂).

As Valence Stabilizer #13b: Examples of three-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofarsenic and are not contained in component heterocyclic rings (As—AsTridentates) that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to:As,As,As-triphenyltriarsacyclohexane ([6]aneAs₃);As,As,As-triphenyltriarsacycloheptane ([7]aneAs₃);As,As,As-triphenyltriarsacyclooctane ([8]aneAs₃);As,As,As-triphenyltriarsacyclononane ([9]aneAs₃);As,As,As-triphenyltriarsacyclodecane ([10]aneAs₃);As,As,As-triphenyltriarsacycloundecane ([11]aneAs₃);As,As,As-triphenyltriarsacyclododecane ([12]aneAs₃);As,As,As-triphenyltriarsacyclohexatriene ([6]trieneAs₃);As,As,As-triphenyltriarsacycloheptatriene ([7]trieneAs₃);As,As,As-triphenyltriarsacyclooctatriene ([8]trieneAs₃);As,As,As-triphenyltriarsacyclononatriene ([9]trieneAs₃);As,As,As-triphenyltriarsacyclodecatriene ([10]trieneAs₃);As,As,As-triphenyltriarsacycloundecatriene ([11]trieneAs₃); andAs,As,As-triphenyltriarsacyclododecatriene ([12]trieneAs₃).

As Valence Stabilizer #13c: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofarsenic and are not contained in component heterocyclic rings (As—AsTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:As,As,As,As-tetraphenyltetraarsacyclooctane ([8]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclononane ([9]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclodecane ([10]aneAs₄);As,As,As,As-tetraphenyltetraarsacycloundecane ([11]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclododecane ([12]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclotridecane ([13]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclotetradecane ([14]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclopentadecane ([15]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclohexadecane ([16]aneAs₄);As,As,As,As,As-tetraphenyltetraarsacycloheptadecane ([17]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclooctadecane ([18]aneAs₄);As,As,As,As-tetraphenyltetraarsacyclononadecane ([19]aneAs₄); andAs,As,As,As-tetraphenyltetraarsacycloeicosane ([20]aneAs₄).

As Valence Stabilizer #13d: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofarsenic and are not contained in component heterocyclic rings (As—AsTridentates, As—As Tetradentates, or As—As Hexadentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to:As,As,As,As,As,As-hexaphenylhexaarsacyclododecane ([12]aneAs₆);As—As,As,As,As,As-hexaphenylhexaarsacyclotridecane ([13]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclotetradecane ([14]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclopentadecane ([15]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclohexadecane ([16]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacycloheptadecane ([17]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclooctadecane ([18]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclononadecane ([19]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacycloeicosane ([20]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacycloheneicosane ([21]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclodocosane ([22]aneAs₆);As,As,As,As,As,As-hexaphenylhexaarsacyclotricosane ([23]aneAs₆); andAs,As,As,As,As,As-hexaphenylhexaarsacyclotetracosane ([24]aneAs₆).

As Valence Stabilizer #14a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of arsenic and are contained in component 5-memberedheterocyclic rings (As—As Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tetraarsoles.

As Valence Stabilizer #14b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof arsenic and are contained in component 5-membered heterocyclic rings(As—As Tetradentates and As—As Hexadentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: hexaarsoles.

As Valence Stabilizer #15a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of arsenic and are contained in a combination of 5-memberedheterocyclic rings and arsine groups (As—As Tridentates, As—AsTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diarsatetraarsoles; and tetraarsatetraarsoles.

As Valence Stabilizer #15b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof arsenic and are contained in a combination of 5-membered heterocyclicrings and phosphine groups (As—As Tridentates, As—As Tetradentates, andAs—As Hexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diarsahexaarsoles; and triarsahexaarsoles.

As Valence Stabilizer #16a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of arsenic and are contained in component 6-memberedheterocyclic rings (As—As Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: cyclotetraarsenins.

As Valence Stabilizer #16b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof arsenic and are contained in component 6-membered heterocyclic rings(As—As Tridentates, As—As Tetradentates, and As—As Hexadentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: cyclohexaarsenins.

As Valence Stabilizer #17a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of arsenic and are contained in a combination of 6-memberedheterocyclic rings and arsine groups (As—As Tridentates, As—AsTetradentates, or As—As Hexadentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: diarsacyclotetraarsenins; and tetraarsacyclotetraarsenins.

As Valence Stabilizer #17b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof arsenic and are contained in a combination of 6-membered heterocyclicrings and arsine groups (As—As Tridentates, As—As Tetradentates, orAs—As Hexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diarsacyclohexaarsenins; and triarsacyclohexaarsenins.

Se Valence Stabilizer #1: Examples of monoselenoethers (Se Monodentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: hydrogen selenide, dimethylselenide, diethyl selenide, dioctyl selenide, diphenyl selenide,dicyclohexyl selenide, tetramethylene selenide, trimethylene selenide,dimethylene selenide, and selenobicycloheptane.

Se Valence Stabilizer #2: Examples of diselenoethers (Se Bidentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to:2,5-dimethyl-3,6-diselenaoctane; 2,5-diselenahexane;2,6-diselenaheptane; 3,7-diselenanonane; 3,6-diselenaoctane; 3-butenylbutyl selenoether (bbs); 4-pentenyl butyl selenoether (pbs); 3-butenylphenyl selenoether (bps); and 4-pentenyl phenyl selenoether (pps).

Se Valence Stabilizer #3: Examples of triselenoethers (Se Bidentates orSe Tridentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:1,3,5-triselenane; 2,5,8-triselenanonane; 3,6,9-triselenaundecane; and2,6,10-triselenaundecane.

Se Valence Stabilizer #4: Examples of tetraselenoethers (Se Bidentates,Se Tridentates, or Se Tetradentates) that meet the requirements for useas “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: 2,6,10,14-tetraselenapentadecane and2,5,8,11-tetraselenadodecane.

Se Valence Stabilizer #5a: Examples of 5-membered heterocyclic ringscontaining one selenium atom (Se Monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dihydroselenophene, selenophene,selenazole, selenapyrroline, selenaphospholene, selenaphosphole,oxaselenole, selenadiazole, selenatriazole, benzodihydroselenophene,benzoselenophene, benzoselenazole, benzoselenaphosphole,dibenzoselenophene, and naphthoselenophene.

Se Valence Stabilizer #5b: Examples of 5-membered heterocyclic ringscontaining two selenium atoms (Se Monodentates or Se Bidentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: diselenole, benzodiselenole, andnaphthodiselenole.

Se Valence Stabilizer #6a: Examples of 6-membered heterocyclic ringscontaining one selenium atom (Se Monodentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dihydroselenopyran, selenopyran,selenazine, selenadiazine, selenaphosphorin, selenadiphosphorin,oxaselenin, benzoselenopyran, dibenzoselenopyran, andnaphthoselenopyran.

Se Valence Stabilizer #6b: Examples of 6-membered heterocyclic ringscontaining two selenium atoms (Se Monodentates or Se Bidentates)thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: dihydrodiselenin, diselenin,benzodiselenin, dibenzodiselenin, and naphthodiselenin.

Se Valence Stabilizer #7: Examples of 5-membered heterocyclic ringscontaining one selenium atom and having at least one additional seleniumatom binding site not contained in a ring (Se Monodentates, Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates, or Se—SeHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce+4 include, but are not limited to:2,5-diseleno-2,5-dihydroselenophene;2,5-bis(selenomethyl)-2,5-dihydroselenophene;2,5-bis(2-selenophenyl)-2,5-dihydroselenophene;2,5-diseleno(selenophene); 2,5-bis(selenomethyl)selenophene;2,5-bis(2-selenophenyl)selenophene; 2,5-diseleno(selenazole);2,5-bis(selenomethyl)selenazole; 2,5-bis(2-selenophenyl)selenazole; and2,5-diseleno-1,3,4-selenadiazole [bismuthselenol].

Se Valence Stabilizer #8: Examples of 6-membered heterocyclic ringscontaining one selenium atom and having at least one additional seleniumatom binding site not contained in a ring (Se Monodentates, Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates, or Se—SeHexadentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce+4 include, but are not limited to:2,6-diseleno-2,5-dihydroselenopyran;2,6-bis(selenomethyl)-2,5-dihydroselenopyran;2,6-bis(2-selenophenyl)-2,5-dihydroselenopyran;2,6-diseleno(selenopyran); 2,6-bis(selenomethyl)selenopyran;2,6-bis(2-selenophenyl)selenopyran; 2,6-diseleno(selenazine);2,6-bis(selenomethyl)selenazine; 2,6-bis(2-selenophenyl)selenazine;2,6-diseleno-1,3,5-selenadiazine; 2-seleno-1-benzoselenopyran;8-seleno-1-benzoselenopyran; and 1,9-diselenodibenzoselenopyran.

Se Valence Stabilizer #9: Examples of 5-membered heterocyclic ringscontaining one selenium atom and having at least one additional seleniumatom binding site contained in a ring (Se Monodentates, Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-2,5-dihydroselenophene;2,2′,2″-tri-2,5-dihydroselenophene; 2,2′-biselenophene;2,2′,2″-triselenophene; 2,2′-biselenazole; 5,5′-biselenazole;2,2′-bi-1,3,4-selenadiazole; 2,2′-biselenanaphthene;2,2′-bibenzoselenazole; and 1,1′-bis(dibenzoselenophene).

Se Valence Stabilizer #10: Examples of 6-membered heterocyclic ringscontaining one selenium atom and having at least one additional seleniumatom binding site contained in a ring (Se Monodentates, Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: 2,2′-bi-2,5-dihydroselenopyran;2,2′,2″-tri-2,5-dihydroselenopyran; 2,2′-biselenopyran;2,2′,2″-triselenopyran; 2,2′-bi-1,4-selenazine;2,2′-bi-1,3,5-selenadiazine; 2,2′-bi-1-benzoselenopyran; and1,1′-bis(dibenzoselenopyran).

Se Valence Stabilizer #11a: Examples of two-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein both binding sites are composed ofselenium (usually selenol or selenoether groups) and are not containedin component heterocyclic rings (Se—Se Bidentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: diselenacyclobutane ([4]aneSe₂);diselenacyclopentane ([5]aneSe₂); diselenacyclohexane ([6]aneSe₂);diselenacycloheptane ([7]aneSe₂); diselenacyclooctane ([8]aneSe₂);diselenacyclobutene ([4]eneSe₂); diselenacyclopentene ([5]eneSe₂);diselenacyclohexene ([6]eneSe₂); diselenacycloheptene ([7]eneSe₂);diselenacyclooctene ([8]eneSe₂); diselenacyclobutadiene ([4]dieneSe₂);diselenacyclopentadiene ([5]dieneSe₂); diselenacyclohexadiene([6]dieneSe₂); diselenacycloheptadiene ([7]dieneSe₂); anddiselenacyclooctadiene ([8]dieneSe₂).

Se Valence Stabilizer #11b: Examples of three-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofselenium (usually selenol or selenoether groups) and are not containedin component heterocyclic rings (Se—Se Tridentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: triselenacyclohexane ([6]aneSe₃);triselenacycloheptane ([7]aneSe₃); triselenacyclooctane ([8]aneSe₃);triselenacyclononane ([9]aneSe₃); triselenacyclodecane ([10]aneSe₃);triselenacycloundecane ([11]aneSe₃); triselenacyclododecane([12]aneSe₃); triselenacyclohexene ([6]eneSe₃); triselenacycloheptene([7]eneSe₃); triselenacyclooctene ([8]eneSe₃); triselenacyclononene([9]eneSe₃); triselenacyclodecene ([10]eneSe₃); triselenacycloundecene([11]eneSe₃); triselenacyclododecene ([12]eneSe₃);triselenacyclohexatriene ([6]trieneSe₃) triselenacycloheptatriene([7]trieneSe₃); triselenacyclooctatriene ([8]trieneSe₃);triselenacyclononatriene ([9]trieneSe₃); triselenacyclodecatriene([10]trieneSe₃); triselenacycloundecatriene ([11]trieneSe₃); andtriselenacyclododecatriene ([12]trieneSe₃).

Se Valence Stabilizer #11c: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofselenium (usually selenol or selenoether groups) and are not containedin component heterocyclic rings (Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetraselenacyclooctane ([8]aneSe₄);tetraselenacyclononane ([9]aneSe₄); tetraselenacyclodecane ([10]aneSe₄);tetraselenacycloundecane ([11]aneSe₄); tetraselenacyclododecane([12]aneSe₄tetraselenacyclotridecane ([13]aneSe₄);tetraselenacyclotetradecane ([14]aneSe₄); tetraselenacyclopentadecane([15]aneSe₄); tetraselenacyclohexadecane ([16]aneSe₄);tetraselenacycloheptadecane ([17]aneSe₄); tetraselenacyclooctadecane([18]aneSe₄); tetraselenacyclononadecane ([19]aneSe₄);tetraselenacycloeicosane ([20]aneSe₄); tetraselenacyclooctadiene([8]dieneSe₄); tetraselenacyclononadiene ([9]dieneSe₄);tetraselenacyclodecadiene ([10]dieneSe₄); tetraselenacycloundecadiene([11]dieneSe₄); tetraselenacyclododecadiene ([12]dieneSe₄);tetraselenacyclotridecadiene ([13]dieneSe₄);tetraselenacyclotetradecadiene ([14]dieneSe₄);tetraselenacyclopentadecadiene ([15]dieneSe₄);tetraselenacyclohexadecadiene ([16]dieneSe₄);tetraselenacycloheptadecadiene ([17]dieneSe₄);tetraselenacyclooctadecadiene ([18]dieneSe₄);tetraselenacyclononadecadiene ([19]dieneSe₄);tetraselenacycloeicosadiene ([20]dieneSe₄);tetraselenacyclooctatetradiene ([8]tetradieneSe₄);tetraselenacyclononatetradiene ([9]tetradieneSe₄);tetraselenacyclodecatetradiene ([10]tetradieneSe₄); andtetraselenacycloundecatetradiene ([11]tetradieneSe₄).

Se Valence Stabilizer #11d: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all binding sites are composed ofselenium (usually selenol or selenoether groups) and are not containedin component heterocyclic rings (Se—Se Tridentates, Se—Se Tetradentates,or Se—Se Hexadentates) that meet the requirements for use as “narrowband” valence stabilizers for Ce⁺⁴ include, but are not limited to:hexaselenacyclododecane ([12]aneSe₆); hexaselenacyclotridecane([13]aneSe₆); hexaselenacyclotetradecane ([14]aneSe₆);hexaselenacyclopentadecane ([5]aneSe₆); hexaselenacyclohexadecane([16]aneSe₆); hexaselenacycloheptadecane ([17]aneSe6);hexaselenacyclooctadecane ([18]aneSe₆); hexaselenacyclononadecane([19]aneSe₆); hexaselenacycloeicosane ([20]aneSe₆);hexaselenacycloheneicosane ([21]aneSe₆hexaselenacyclodocosane([22]aneSe₆); hexaselenacyclotricosane ([23]aneSe₆);hexaselenacyclotetracosane ([24]aneSe₆); hexaselenacyclododecatriene([12]trieneSe₆); hexaselenacyclotridecatriene ([13]trieneSe₆);hexaselenacyclotetradecatriene ([14]trieneSe₆);hexaselenacyclopentadecatriene ([15]trieneSe₆);hexaselenacyclohexadecatriene ([16]trieneSe₆);hexaselenacycloheptadecatriene ([17]trieneSe₆); andhexaselenacyclooctadecatriene ([18]trieneSe₆).

Se Valence Stabilizer #12a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of selenium and are contained in component 5-memberedheterocyclic rings (Se—Se Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tetraselenophenes; tetraselenaphospholes; tetraoxaselenoles;and tetradiselenoles.

Se Valence Stabilizer #12b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof selenium and are contained in component 5-membered heterocyclic rings(Se—Se Tridentates or Se—Se Tetradentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: hexaselenophenes; hexaselenaphospholes;hexaoxaselenoles; and hexadiselenoles.

Se Valence Stabilizer #13a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of selenium and are contained in a combination of 5-memberedheterocyclic rings and selenol and selenoether groups (Se—SeTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diselenatetraselenophenes; tetraselenatetraselenophenes;diselenatetradiselenoles; and tetraselenatetradiselenoles.

Se Valence Stabilizer #13b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof selenium and are contained in a combination of 5-memberedheterocyclic rings and selenol or selenoether groups (Se—Se Tridentatesor Se—Se Hexadentates) that meet the requirements for use as “narrowband” valence stabilizers for Ce⁺⁴ include, but are not limited to:diselenahexaselenophenes; and triselenahexaselenophenes.

Se Valence Stabilizer #14a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of selenium and are contained in component 6-memberedheterocyclic rings (Se—Se Tetradentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: tetraselenopyrans; tetraselenaphosphorins;tetraselenadiphosphorins; tetraoxaselenins; and tetradiselenins.

Se Valence Stabilizer #14b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof selenium and are contained in component 6-membered heterocyclic rings(Se—Se Tridentates or Se—Se Hexadentates) that meet the requirements foruse as “narrow band” valence stabilizers for Ce⁺⁴ include, but are notlimited to: hexaselenopyrans; hexaselenaphosphorins;hexaselenadiphosphorins; hexaoxaselenins; and hexadiselenins.

Se Valence Stabilizer #15a: Examples of four-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all four binding sites arecomposed of selenium and are contained in a combination of 6-memberedheterocyclic rings and selenol or selenoether groups (Se—SeTetradentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:diselenatetraselenopyrans; tetraselenatetraselenopyrans;diselenatetraselenaphosphorins; tetraselenatetraselenaphosphorins;diselenatetraoxaselenins; tetraselenatetraoxaselenins;diselenatetradiselenins; and tetraselenatetradiselenins.

Se Valence Stabilizer #15b: Examples of six-membered macrocyclics,macrobicyclics, and macropolycyclics (including catapinands, cryptands,cyclidenes, and sepulchrates) wherein all six binding sites are composedof selenium and are contained in a combination of 6-memberedheterocyclic rings and selenol or selenoether groups (Se—Se Tridentates,Se—Se Tetradentates, or Se—Se Hexadentates) that meet the requirementsfor use as “narrow band” valence stabilizers for Ce⁺⁴ include, but arenot limited to: diselenahexaselenopyrans; triselenahexaselenopyrans;diselenahexaselenaphosphorins; triselenahexaselenaphosphorins;diselenahexaoxaselenins; triselenahexaoxaselenins;diselenahexadiselenins; and triselenahexadiselenins.

Se Valence Stabilizer #16: Examples of 1,3-diselenoketones(diseleno-beta-ketonates), 1,3,5-triselenoketones,bis(1,3-diselenoketones), and poly(1,3-diselenoketones) (Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: hexafluoropentanediselenone;1,3-diphenyl-1,3-propanediselenone; selenobenzoylselenopinacolone;diselenocyclohexoylmethane; diphenylpentanetriselenoate;tetramethylnonanetriselenoate; hexafluoroheptanetriselenoate;trifluoroheptanetriselenoate; 1-(2-thienyl)-1,3-butanediselenone,1-(2-naphthyl)-1,3-butanediselenone, andtrifluoroselenoacetylselenocamphor.

Se Valence Stabilizer #17: Examples of 1,1-diselenolates,bis(1,1-diselenolates), and poly(1,1-diselenolates) (Se—Se Bidentatesand Se—Se Tetradentates) that meet the requirements for use as “narrowband” valence stabilizers for Ce⁺⁴ include, but are not limited to:1,1-dicyano-2,2-ethylene diselenolate;1,1-dicarboalkoxy-2,2-ethylenediselenolate;1,1-di(trifluoromethyl)-2,2-ethylene diselenolate;1,1-di(pentafluorophenyl)-2,2-ethylene diselenolate;1-pentamethylene-2,2-ethylene diselenolate; and 1-nitroethylenediselenolate.

Se Valence Stabilizer #18: Examples of diselenocarbamates,bis(diselenocarbamates), and poly(diselenocarbamates) (includingN-hydroxydiselenocarbamates and N-mercaptodiselenocarbamates) (Se—SeBidentates, Se—Se Tridentates, and Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: dimethyldiselenocarbamate;di(trifluorodimethyl)diselenocarbamate; diethyldiselenocarbamate;dipropyldiselenocarbamate; diisopropyldiselenocarbamate;dibutyldiselenocarbamate; ditertbutyldiselenocarbamate;dicyanamidodiselenocarbamate; azidoselenoformates;diphenyldiselenocarbamate; di(pentafluorophenyl)diselenocarbamate;dibenzyldiselenocarbamate; dinaphthyldiselenocarbamate;dicyclohexyldiselenocarbamate; dinorbornyldiselenocarbamate;diadamantyldiselenocarbamate; pyrrolidinodiselenocarbamate;piperidinodiselenocarbamate; morpholinodiselenocarbamate;thiamorpholinodiselenocarbamate; 3-pyrrolinodiselenocarbamate;pyrrolodiselenocarbamate; oxazolodiselenocarbamate;isoxazolodiselenocarbamate; thiazolodiselenocarbamate;isothiazolodiselenocarbamate; indolodiselenocarbamate;carbazolodiselenocarbamate; pyrazolinodiselenocarbamate;imidazolinodiselenocarbamate; pyrazolodiselenocarbamate;imidazolodiselenocarbamate; indazolodiselenocarbamate; andtriazolodiselenocarbamate.

Se Valence Stabilizer #19: Examples of triselenophosphoric acids(phosphorotriselenoic acids), bis(triselenophosphoric acids),poly(triselenophosphoric acids), and derivatives thereof (Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: triselenophosphoric acid,O-phenyltriselenophosphoric acid, O-benzyltriselenophosphoric acid,O-cyclohexyltriselenophosphoric acid, O-norbornyltriselenophosphoricacid, O,Se-diphenyltriselenophosphoric acid,O,Se-dibenzyltriselenophosphoric acid,O,Se-dicyclohexyltriselenophosphoric acid, andO,Se-dinorbornyltriselenophosphoric acid.

Se Valence Stabilizer #20: Examples of diselenophosphoric acids(phosphorodiselenoic acids), bis(diselenophosphoric acids),poly(diselenophosphoric acids), and derivatives thereof (Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: diselenophosphoric acid,O-phenyldiselenophosphoric acid, O-benzyldiselenophosphoric acid,O-cyclohexyldiselenophosphoric acid, O-norbornyltriselenophosphoricacid, O,O-diphenyldiselenophosphoric acid,O,O-dibenzyldiselenophosphoric acid, O,O-dicyclohexyldiselenophosphoricacid, and O,O-dinorbornyldiselenophosphoric acid.

Se Valence Stabilizer #21: Examples of tetraselenophosphoric acids(phosphorotetraselenoic acids), bis(tetraselenophosphoric acids),poly(tetraselenophosphoric acids), and derivatives thereof (Se—SeBidentates, Se—Se Tridentates, Se—Se Tetradentates) that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: tetraselenophosphoric acid,Se-phenyltetraselenophosphoric acid, Se-benzyltetraselenophosphoricacid, Se-cyclohexyltetraselenophosphoric acid,Se-norbornyltetraselenophosphoric acid,Se,Se-diphenyltetraselenophosphoric acid,Se,Se-dibenzyltetraselenophosphoric acid,Se,Se-dicyclohexyltetraselenophosphoric acid, andSe,Se-dinorbornyltetraselenophosphoric acid.

Se Valence Stabilizer #22: Examples of diselenocarbonates,triselenocarbonates, bis(diselenocarbonates), andbis(triselenocarbonates), (Se—Se Bidentates and S—S Tetradentates) thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: Se,Se-diethyldiselenocarbonate;Se,Se-diisopropyldiselenocarbonate; Se,Se-diphenyldiselenocarbonate;Se,Se-dibenzyldiselenocarbonate; Se,Se-dicyclohexyldiselenocarbonate;Se,Se-dinorbornyldiselenocarbonate; diethyltriselenocarbonate;diisopropyltriselenocarbonate; diphenyltriselenocarbonate;dibenzyltriselenocarbonate; dicyclohexyltriselenocarbonate; anddinorbornyltriselenocarbonate.

Se Valence Stabilizer #23: Examples of selenocyanate ligands (Semonodentates) that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to:selenocyanate (—SeCN).

Se Valence Stabilizer #24: Examples of selenolates (Se monodentates)that meet the requirements for use as “narrow band” valence stabilizersfor Ce⁺⁴ include, but are not limited to: selenophenol; andnaphthaleneselenol.

Miscellaneous Valence Stabilizer #1: Examples of diene, bicyclicandtricyclic hydrocarbon ligands that meet the requirements for use as“narrow band” valence stabilizers for Ce⁺⁴ include, but are not limitedto: cyclopentadiene; azulene; carotene; norbornane; and adamantane.

Miscellaneous Valence Stabilizer #2: Examples of cyanide and relatedligands that meet the requirements for use as “narrow band” valencestabilizers for Ce⁺⁴ include, but are not limited to: cyanide (—CN); andfulminate (—CNO).

Miscellaneous Valence Stabilizer #3: Examples of carbonyl ligands thatmeet the requirements for use as “narrow band” valence stabilizers forCe⁺⁴ include, but are not limited to: carbonyl (—CO); and carbon dioxide(CO₂) ligands.

Miscellaneous Valence Stabilizer #4: Examples of halogens that meet therequirements for use as “narrow band” valence stabilizers for Ce⁺⁴include, but are not limited to: fluorine; chlorine; bromine; andiodine.

Miscellaneous Valence Stabilizer #5: Examples of hydroxo and oxofunctionalities that meet the requirements for use as “narrow band”valence stabilizers for Ce⁺⁴ include, but are not limited to: water(H₂O); dioxygen (O₂); oxide (O²⁻); hydroxide (OH—); peroxo groups (O₂²⁻); and superoxo groups (O₂ ⁻).

As discussed above, the properties of a particular Ce⁺⁴-containingcomplex can be altered by changing the substituent groups on thesegeneral classes of valence stabilizers. This can influence theeffectiveness of corrosion inhibition normally achieved using thatspecific complex.

4e) Mixed Inorganic/Organic Valence Stabilizers

Mixing inorganic and organic valence stabilizers in a conversion coatingsolution will often result in a coating with poor corrosion-inhibitingproperties because of cross interference. Inorganic and organicstabilizers interact with Ce⁺⁴ in different ways. For example, inorganicvalence stabilizers will perform their function by forming a shell ofoctahedrally or icosahedrally coordinated anionic species around acaptured Ce⁺⁴ ion. Therefore, the net charge of these inorganicCe⁺⁴-stabilizer complexes is always negative. Organic species stabilizeby the formation of a “hard bond” between the bonding atom in thestabilizer (e.g., nitrogen or oxygen) and the Ce⁺⁴ ion. The net chargeof these complexes is often positive. If these two very different typesof stabilization ligands are combined, then the magnitude of the chargeon the stabilized complex can be reduced significantly. The performanceof organic or inorganic stabilized corrosion inhibitor complexes hasbeen found to be directly related to the ability of the complex to formand sustain a thick electrostatic barrier layer. Additionally, a mixedstabilizer can have a poorly developed electrostatic field and anon-optimal packing around the Ce⁺⁴ ion, resulting in a complex withless resistance to aqueous attack. Mixed organic/inorganic stabilizedCe⁺⁴ coatings will generally perform more poorly than coatings that haveexclusively organic or inorganic valence stabilizers for this reason.

4f) Valence Stabilizers for Tetravalent Praseodymium and Terbium

The PrIV and ThIV ions form very few stable complexes with inorganic ororganic compounds. Examples of typical wide band inorganic ligands forPrIV and ThIV include periodates, tellurates, tungstates, molybdates,vanadates, carbonates, and phosphates. Under certain circumstances,narrow band inorganic ligands such as oxygen, fluorides, antimonates,iodates, and bromates may be acceptable. Examples of typical organicligands for PrIV and ThIV include dithiocarbamates, dithiolenes,dithiols, dithioketones, biguanides, oximes, Schiff bases, and some azocompounds. PrIV and ThIV may be used in the future with compounds notcurrently identified.

5) Additional Solubility Control Agents

One of the roles of the valence stabilizer is to allow for the formationof a tetravalent cerium, praseodymium, or terbium complex that has aspecific solubility range. The anions or cations present in the coatingsolution may be sufficient to form a Ce⁺⁴—, Pr⁺⁴—, or Tb⁺⁴-containingcompound within the conversion coating that exhibits the desiredsolubility characteristics. However, additional solubility control maybe desirable to optimize the performance of the tetravalent cerium-,tetravalent praseodymium-, or tetravalent terbium-valence stabilizercomplex. The use of an additional solubility control agent is optional,not required.

Both the organic and inorganic valence stabilizers described above mayneed some kind of additional solubility control that can be in the formof either inorganic or organic compounds. The key to selectingsolubility control agents is to match the cationic or anionic modifierswith individual Ce⁺⁴—, Pr⁺⁴—, or Tb⁺⁴-valence stabilizer combinations.Some cations or anions may work to optimize one Ce⁺⁴—, Pr⁺⁴—, orTb⁺⁴-valence stabilizer complex, but this does not necessarily mean theywill optimize the solubility of a different complex.

The initial formation of a conversion coating may produce Ce⁺⁴, Pr⁺⁴, orTb⁺⁴ compounds with solubilities greater than optimal. A post-depositiontreatment can be applied to the coating as a remedial treatment or as adesired process step. Additional solubility control agents applied to awork piece can enhance the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ content of the coating byforming more insoluble compounds in place. Application of a secondsolution after the conversion coating process has been found to resultin enhanced solubility control of Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ in the conversioncoating.

Additional solubility control agents are typically applied as a secondsolution. Otherwise, these cations or anions would begin to precipitatecerium-, praseodymium-, or terbium-containing compounds in theconversion coating solution, depleting it of cerium, praseodymium, orterbium prior to treating the work piece. In general, fine tuning ofsolubility by cationic species is typical for Ce⁺⁴—, Pr⁺⁴—, orTb⁺⁴-stabilizer combinations when an inorganic valence stabilizer isused, and by anionic species when an organic valence stabilizer is used.

The need for an additional solubility control agent may be illustratedfor the situation where molybdate is used as a valence stabilizer for aCe⁺⁴ conversion coating. Cationic species are necessary to deposit aCe⁺⁴/molybdate complex within the coating (the net charge on aCe⁺⁴/heteropolymolybdate anion may either be −2, −4, or −8). Thecationic species needed to balance the charge and form a compound isusually supplied from cations already present in the conversion coatingsolution and/or by cations being pulled into the solution from the workpiece. However, if the Ce⁺⁴/molybdate complex composed of the availablecations has a much greater solubility than desired, then additionalsolubility control agents can be employed. The differences ineffectiveness of conversion coatings on various alloy compositions islikely a reflection of the influence that the composition of the alloyitself has on the solubility of the deposited conversion coating.Similarly, anions present in a conversion coating solution or sourcematerial will be incorporated in a Ce⁺⁴ compound that requires anegative charge balance. This is frequently observed with Ce⁺⁴/organicvalence stabilizer combinations.

Additional solubility control can be achieved through the use ofnon-toxic inorganic cations which include, but are not limited to: H⁺,Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, NH₄ ⁺, Mg⁺², Ca⁺², Sr⁺², Y⁺³, La⁺³, Ce⁺³, Ce⁺⁴,Nd⁺³, Pr⁺³, Sc⁺³, Sm⁺³, Eu⁺³, Eu⁺², Gd⁺³, Tb⁺³, Dy⁺³, Ho⁺³, Er⁺³, Tm⁺³,Yb⁺³, Lu⁺³, Ti⁺⁴, Zr⁺⁴, Ti⁺³, Hf⁺⁴, Nb⁺⁵, Ta⁺⁵, Nb⁺⁴, Ta⁺⁴, Mo⁺⁶, W⁺⁶,Mo⁺⁵, W⁺⁵, Mo⁺⁴, W⁺⁴, Mn⁺², M⁺³, Mn⁺⁴, Fe⁺², Fe⁺³, Co⁺², Co⁺³, Ru⁺²,Ru⁺³, Ru⁺⁴, Rh⁺³, Ir⁺³, Rh⁺², Ir⁺², Pd⁺⁴, Pt⁺⁴, Pd⁺², Pt⁺², Cu⁺, Cu⁺²,Cu⁺³, Ag⁺, Ag⁺², Ag⁺³, Au⁺, Au⁺², Au⁺³, Zn⁺², Al⁺³, Ga⁺³, Ga⁺, In⁺³,In⁺, Ge⁺⁴, Ge⁺², Sn⁺², Sn⁺⁴, Sb⁺³, Sb⁺⁵, Bi⁺³, and Bi⁺⁵. Anywater-soluble compound that contains these cations can be used for thispurpose. Nitrates, chlorides, bromides, and perchlorates of thesecations offer inexpensive water-soluble precursors, although many otherwater-soluble precursors exist.

Cationic solubility control may also be achieved through the use ofnontoxic organic cations that include, but are not limited to:quaternary ammonium compounds (NR₄ ⁺, where R can be any combination ofalkyl, aromatic, or acyclic organic substituents, such as themethyltriethylammonium ion); organics that contain at least one N⁺ site(such as pyridinium or thiazolium cations); organics that contain atleast one phosphonium site (P⁺, such as the benzyltriphenylphosphoniumion); organics that contain at least one stibonium site (Sb⁺, such asthe tetraphenylstibonium ion); organics that contain at least oneoxonium site (O⁺, such as pyrylium cations); organics that contain atleast one sulfonium site (S⁺, such as the triphenylsulfonium ion); andorganics that contain at least one iodonium site (I⁺, such as thediphenyliodonium ion).

The quaternary ammonium compounds, organics containing at least oneN⁺site, and organics containing at least one oxonium site are the mostimportant of these classifications because of the very large number ofstable cations that are available. Water-soluble precursors for theseorganic cations are desirable in order to maximize the amount ofmaterial available in the appropriate conversion coating solution.Fluorides, chlorides, and bromides offer the most water-solubleprecursors for these organic cations, although lower molecular weightnitrates and perchlorates of these cations (e.g., tetramethylammonium)are also acceptable water-soluble precursors. Larger molecular weightnitrates and perchlorates are not generally acceptable as precursorsbecause of their low water solubility.

Although it is less desirable, toxic inorganic or organic cations can beused as additional solubility control agents. Examples of toxicinorganic cations that can be used include, but are not limited to:Be⁺², Ba⁺², V⁺⁵, V⁺⁴, V⁺³, Cr⁺³, Ni⁺², Ni⁺⁴, Os⁺⁴, Cd⁺², Hg⁺¹, Hg⁺²,Tl⁺, Tl⁺³, As⁺³, As⁺⁵, Pb⁺², and Pb⁺⁴. Examples of toxic organic cationsinclude, but are not limited to: organic compounds that contain at leastone arsonium site (As⁺, an example being the tetraphenylarsonium ion)and organic compounds that contain at least one selenonium site (Se⁺, anexample being the triphenylselenonium ion). Use of these materials foradditional solubility control may be desirable in some specificinstances where the toxicity of the coating bath is of limitedimportance to the operator. Water-soluble precursors for these toxiccations are desirable in order to maximize the amount of availablecation for solubility control. In general, the nitrates, fluorides,chlorides, bromides, and perchlorates of these cations offer the highestwater solubility.

Additional solubility control can also be achieved through the use ofnontoxic inorganic anions, especially for Ce⁺⁴/, Pr⁺⁴/, or Tb⁺⁴/organicvalence stabilizer combinations. Water-soluble precursors for theseinorganic anions are desirable in order to maximize the amount ofmaterial available in the appropriate conversion coating solution. Theseinclude, but are not limited to: fluorotitanates, chlorotitanates,fluorozirconates, chlorozirconates, fluoroniobates, chloroniobates,fluorotantalates, chlorotantalates, molybdates, tungstates,permanganates, fluoromanganates, chloromanganates, fluoroferrates,chloroferrates, fluorocobaltates, chlorocobaltates, fluorozincates,chlorozincates, borates, fluoroborates, fluoroaluminates,chloroaluminates, carbonates, silicates, fluorosilicates,fluorostannates, nitrates, nitrites, azides, phosphates, phosphites,phosphonates, phosphinites, thiophosphates, thiophosphites,thiophosphonates, thiophosphinites, fluorophosphates, fluoroantimonates,chloroantimonates, sulfates, sulfites, sulfonates, thiosulfates,dithionites, dithionates, fluorosulfates, tellurates, fluorides,chlorides, chlorates, perchlorates, bromides, bromates, iodides,iodates, periodates, and heteropolyanions (e.g., heteropolymolybdates,silicomolybdates).

Additional solubility control can also be achieved through the use of analmost unlimited number of non-toxic organic anions (e.g., organics withdifferent carboxylates or acid groups). Examples include, but are notlimited to: ferricyanides; ferrocyanides; cyanocobaltates;cyanocuprates; cyanomanganates; cyanates; cyanatoferrates;cyanatocobaltates; cyanatocuprates; cyanatomanganates; thiocyanates;thiocyanatoferrates; thiocyanatocobaltates; thiocyanatocuprates;thiocyanatomanganates; cyanamides; cyanamidoferrates;cyanamidocobaltates; cyanamidocuprates; cyanamidomanganates;nitritoferrates; nitritocobaltates; azides; (thio)carboxylates,di(thio)carboxylates, tri(thio)carboxylates, or tetra(thio)carboxylates[useful representatives including, but not limited to, acetic acid,benzoic acid, succinic acid, fumaric acid, salicylic acid, lactic acid,tartaric acid, antimonyl tartrates, cinnamic acid, adipic acid, phthalicacid, terephthalic acid, citric acid, ascorbic acid, malic acid, malonicacid, oxalic acid, stearic acid, gallic acid, naphthenic acid, camphoricacid, nitrosalicylic acid, aminosalicylic acid, acetylsalicylic acid,sulfosalicylic acid, nitrobenzoic acid, perfluoroC₂₋₁₆carboxylic acids,trinitrobenzoic acid, chlorobenzoic acid, anisic acid, iodobenzoic acid,anthranilic acid, mandelic acid, toluic acid, nicotinic acid,isonicotinic acid, pyrazolecarboxylic acid, picrolonic acid, quinaldicacid, diphenic acid, benzoquinaldic acid, quinolinecarboxylic acid,isoquinolinecarboxylic acid, triazinecarboxylic acid, (thio)carbonicacids, (thio)carbamic acids, trimethylhexylic acid, tetrafluorophthalicacid, ethylenediaminetetraacetic acid, toluoylpropionic acid,lactobionic acid, octylthiopropionate, lipoic acid,methylbenzoylpropionic acid, anthracenesuccinic acid,benzothiazolecarboxylic acid, phenylacetic acid, glycolic acid,thioglycolic acid, benzothiazolylthiosuccinic acid,benzothiazolylthiopropionic acid, phenylanthranilic acid,furancarboxylic acid, nitrofuroic acid, phosphonobutanetricarboxylicacid, benzothiazolylthiosuccinic acid, N-phosphonomethylglycine,cresoxyacetic acid, aminobutyric acid, alanine, asparagine, cysteine,glutamine, glycine, leucine, methionine, phenylalanine, proline, serine,threonine, tryptophan, tyrosine, valine, glutamic acid, aspartic acid,arginine, histidine, lysine, trihydroxyglutaric acid, phenoxyaceticacid, hydroxynaphthoic acid, phenylbutyric acid, hydroxyphosphonoaceticacid, tropic acid, aminophenylpropionic acid, dihydrocinnamic acid,hydroxycinnamic acid, cinchomeronic acid, aurintricarboxylic acid,benzotriazolecarboxylic acid, hydroxyphosphonoacetic acid, cyanuricacid, barbituric acid, violuric acid, diphenylvioluric acid, dilituricacid, thiobarbituric acid, cresotic acid, trimethylhexylic acid,nitrilotriacetic acid, N,N′-terephthaloylbis(aminocaproic acid),ethyleneglycolbis(aminoethylether)tetraacetic acid,diethylenetriaminepentaacetic acid, 2-phosphonobutanetricarboxylic acid,N,N′-bis(2-hydroxysuccinyl)ethylenediamine, nicotinic acid, naptalam,nitrobenzoic acid, nonylphenoxyacetic acid, and olsalazine];(thio)phenolates, di(thio)phenolates, tri(thio)phenolates, ortetra(thio)phenolates [useful representatives including, but not limitedto, pyrocatechol, resorcinol, picric acid, styphnic acid, pyrogallol,purpurin, purpurogallin, benzopurpurin, gallein, thiophenol, rhodizonicacid, kojic acid, chromotropic acid, carminic acid, fluorescein, tannicacid, and humic acid]; (thio)phosphonates, di(thio)phosphonates, ortri(thio)phosphonates [useful representatives including, but not limitedto, diethylphosphonic acid, diphenylphosphonic acid,nitrophenylphosphonic acid, perfluoroC₂₋₁₆phosphonic acids,benzenephosphonic acid, phytic acid, hydroxyethylidenebisphosphonicacid, nitrilotrimethylenephosphonic acid, aminomethylenephosphonic acid,etidronic acid, ethylphosphonic acid, chloroethylphosphonic acid,ethylenediaminotetramethylenephosphonic acid, laurylhydroxydiphosphonicacid, methylaminodimethylenephosphonic acid, alkyl(aryl)diphosphonicacids, N-cetylaminoethanediphosphonic acid,carboxyhydroxymethylphosphonic acid (hpa), oxyethylidenediphosphonicacid, polycaproamidophosphonates, phenylethanetriphosphonic acid,oxidronic acid, and pamidronic acid]; (thio)phosphonamides,di(thio)phosphonamides, or tri(thio)phosphonamides [usefulrepresentatives including, but not limited to, phosphoramidic acid,phosphordiamidic acid (diamidophosphonic acid), and phosphoramidothioicacid]; amino(thio)phosphonates, diamino(thio)phosphonates, ortriamino(thio)phosphonates; imino(thio)phosphonates ordiimino(thio)phosphonates; (thio)sulfonates, di(thio)sulfonates, ortri(thio)sulfonates [useful representatives including, but not limitedto, methanesulfonic acid, benzenesulfonic acid, aminobenzenesulfonicacid (sulfanilic acid), nitrobenzenesulfonic acid, phenylsulfonic acid,naphthalenesulfonic acid, nitronaphthalenesulfonic acid, oxinesulfonicacid, alizarinsulfonic acid, benzidinesulfonic acid, flavianic acid,camphorsulfonic acid, diiodophenolsulfonic acid (sozoiodol),8-hydroxyquinoline-5-sulfonic acid,7-nitro-8-hydroxyquinoline-5-sulfonic acid, benzotriazolesulfonic acid,bis(trifluoromethyl)benzenesulfonic acid,diiododihydroxybenzophenonesulfonic acid,p-amino-p′-ethoxydiphenylamine-o-sulfonic acid,1-amino-2-naphthol-4-sulfonic acid, 1,2-diaminoanthraquinone-3-sulfonicacid, 1,5-dinitro-2-naphthol-7-sulfonic acid, perfluoroC₂₋₆sulfonicacids, benzenedisulfonic acid, phenyldisulfonic acid,naphthalenedisulfonic acid, 3,6-naphtholdisulfonic acid,indigodisulfonic acid, benzidinedisulfonic acid,carboxyiodobenzenesulfonic acids, N-benzeneaminomethanesulfonic acid(ams), amido-G-acid, amido-R-acid, naphthalene(di)sulfonic acid(Armstrong's acid), amsonic acid, Badische acid, camphorsulfonic acid,chrysophenine, Cassella's acid, chromotropic acid, Cleve's acid, croceicacid, anthracenesulfonic acid, hydroxyquinolinesulfonic acid,hydrazinobenzenesulfonic acid, indigo carmine, indoxyl, isatinsulfonicacid, indican, lignosulfonic acid, metanil yellow, metanilic acid,naphthoquinonesulfonic acid, Nuclear Fast Red, naphthol(di)sulfonicacid, naphthylamine(di)sulfonic acid, Orange I, orthanilic acid,phenol(di)sulfonic acid, methylenedinaphthalenesulfonic acid, methylorange, and piperazinediethanesulfonic acid (pipes)];(thio)sulfonamides, di(thio)sulfonamides, or tri(thio)sulfonamides;amino(thio)sulfonates, diamino(thio)sulfonates, ortriamino(thio)sulfonates; imino(thio)sulfonates (including sulfamates)or diimino(thio)sulfonates (including disulfamates) [usefulrepresentatives including, but not limited to, methylsulfamic acid andphenylsulfamic acid]; (thio)borates, di(thio)borates, or (thio)boronates[useful representatives including, but not limited to, phenylboric acidand borotartaric acid]; organic silicates; and stibonates [usefulrepresentatives including, but not limited to, antimonyl tartrate andbenzenestibonic acid]. Water-soluble precursors for these organic anionsare desirable to maximize the amount available in the appropriateconversion coating solution.

Finally, toxic inorganic or organic anions can be used as additionalsolubility control agents, although this is less desirable. Examples oftoxic inorganic anions include, but are not limited to: arsenates,arsenites, fluoroarsenates, chloroarsenates, selenates, selenites,fluorothallates, chlorothallates, iodomercury anions (e.g., Nessler'sreagent), thiocyanatomercury anions (e.g., Behren's reagent),chloromercurates, bromomercurates, osmates, fluoronickelates, chromates,Reinecke's salt, and vanadates. Examples of toxic organic anions includecyanides; cyanochromates; cyanonickelates; cyanatochromates;cyanatonickelates; thiocyanatochromates; thiocyanatonickelates;cyanamidochromates; cyanamidonickelates; nitritonickelates; arsonates,diarsonates, or triarsonates [useful representatives including, but notlimited to, propylarsonic acid, phenylarsonic acid, hydroxyphenylarsonicacid, benzenearsonic acid, methylbenzenearsonic acid,hydroxybenzenearsonic acid, and nitrobenzenearsonic acid]; organicselenates, diselenates, or triselenates. These materials may benecessary in some specific instances for additional solubility controlwhere coating bath toxicity is of limited importance. Water-solubleprecursors for these anions are desirable in order to maximize theamount of available anion to interact with the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴complex. The alkali or ammonium species of these anions typically offerthe greatest water solubility.

6) Agents to Increase Color-Fastness of Coating

Conversion coatings will frequently be colored to improve the aestheticnature of the work piece, as well as to aid in the identification ofcoated versus uncoated areas. Long-term exposure to high energywavelengths (i.e., the ultraviolet wavelengths of sunlight) may fade ordim the color of the coated work piece. The conversion coating solutionmay include agents that improve the color-fastness of the coating.Typically, these are termed “UV blockers” in the paint and coatingsliterature. Active UV blockers are typically dark in color and functionby absorbing nearly all of the light energy. Passive UV blockers arelight in color and function by reflecting back nearly all of the lightenergy. Examples of active UV blockers include carbon black, graphiteand phthalocyanines. Examples of passive UV blockers include titaniumoxide, tin oxide, silicon oxide, silicates, or aluminosilicates.

7) Agents to Add Color to the Formed Coating

It is desirable that coatings placed directly onto metal work pieces becolored so as to provide a metric of coating thickness, to identifyuncoated areas, or even for aesthetic purposes. Rare earth compoundsoften exhibit no color in the coating, or result in very pale coloredcoatings. For this reason, it may optionally be advantageous to add asolvent-soluble (typically water-soluble) colorant to the conversioncoating solution. Dye chemicals such as vat dyes (i.e., indigo oranthraquinone), mordant and lake dyes (i.e., alizarin), direct dyes(i.e., mauve), disperse dyes (i.e., quinones), azo dyes, triazene dyes,triphenylmethane dyes (i.e., malachite green), azine dyes (i.e.,methylene blue), formazan dyes, phthalocyanine dyes, Schiff Base dyes,or naturally-occurring dyes (such as anthocyanins, carotenoids,quinines, melanins, ommochromes, pterins, porphyrins, and indigoids), orcombinations thereof, can be used for this purpose. Inorganic pigmentsare also acceptable.

B. Solution Composition and Preparation

Additional important process considerations include chemicalconcentrations, pH of the coating solution, redox potential of thecoating solution, application temperature, and contact time.

1) Solvents

Water is a typical solvent for these conversion coating solutions due toits availability and low cost. Other solvents or combinations of waterwith other solvents (such as alcohols, ketones, etc.) may also be usedif desired. However, these processes will be more costly than thoseusing water exclusively.

2) Cerium, Praseodymium, or Terbium Concentration

The maximum concentration of the cerium, praseodymium, or terbium sourcedepends upon the solubility of the specific source used. Anyconcentration exceeding this precursor solubility will result inundissolved solid material that will not be incorporated into theconversion coating and may even act as flaws in the coating. The ambienttemperature processes outlined here produce Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴conversion coatings with exceptional corrosion-inhibiting character.Therefore, the solubility of the cerium, praseodymium, or terbiumsources in water at or near ambient temperature (25° C.) should be themaximum amount of the cerium, praseodymium, or terbium source that isadded. Since the solubility of virtually all materials in waterincreases with temperature, more cerium, praseodymium, or terbium can beadded to the conversion coating solution if the temperature of the bathis increased from ambient. Although higher temperatures lead to higherallowable concentrations of cerium, praseodymium, or terbium precursors,this is unnecessary and adds to the cost of the process.

Acidic pHs will typically increase the solubility of many inorganicmaterials, thereby increasing the concentration of cerium, praseodymium,or terbium available in solution. A general estimate of the maximumconcentration of cerium or praseodymium in the conversion coatingsolution at ambient conditions can be determined from the solubilitiesof some of the more desirable cerium or praseodymium sources listed inTable 3. The solubility of terbium sources is often comparable topraseodymium sources.

TABLE 3 Solubilities of Some Cerium and Praseodymium Sources underAmbient Conditions [Maximum Concentration of Cerium or Praseodymium inSolution] (at or near 25° C. and at or near pH 7) Cerium or PraseodymiumSource Solubility in Water (mole/L) Cerium (III) nitrate 1.5 × 10⁰  Cerium (III) sulfate 1.2 × 10⁻¹ Cerium (III) perchlorate 2.0 × 10⁰  Cerium (III) chloride 4.1 × 10⁰   Cerium (III) bromide 1.0 × 10⁰  Cerium (III) iodide 1.0 × 10⁻¹ Cerium (III) bromate 1.0 × 10⁰   Cerium(III) formate 1.3 × 10⁻² Cerium (III) acetate 6.6 × 10⁻¹ Cerium (III)propionate 4.6 × 10⁻¹ Cerium (III) butyrate 7.7 × 10⁻² Cerium (III)dimethylphosphate 7.6 × 10⁻¹ Ammonium cerium (III) nitrate 5.7 × 10⁰  Magnesium cerium (III) nitrate 4.3 × 10⁻¹ Ammonium cerium (III) sulfate7.0 × 10⁻² Cerium (IV) chloride 1.0 × 10⁰   Cerium (IV) perchlorate 1.0× 10⁰   Cerium (IV) sulfate 5.0 × 10⁻¹ Cerium (IV) nitrate 1.0 × 10⁰  Cerium (IV) acetate 5.0 × 10⁻¹ Ammonium cerium (IV) nitrate 2.6 × 10⁰  Ammonium cerium (IV) sulfate 5.0 × 10⁻¹ Praseodymium (III) nitrate 1.4 ×10⁰   Praseodymium (III) sulfate 3.1 × 10⁻¹ Praseodymium (III)perchlorate 2.2 × 10⁰   Praseodymium (III) chloride 8.9 × 10⁰  Praseodymium (III) bromide 1.0 × 10⁻¹ Praseodymium (III) iodide 1.0 ×10⁰   Praseodymium (III) bromate 2.9 × 10⁰   Praseodymium (III) acetate6.3 × 10⁻¹ Magnesium praseodymium (III) nitrate 4.1 × 10⁻¹

The depletion of cerium, praseodymium, or terbium from the coatingsolution below an acceptable level is a function of the amount of metalsurface area being coated prior to regeneration of the solution. Acoating applied to a very large surface area may deplete the solution tothe point that subsequent solution applications no longer form effectivecoatings. Less cerium, praseodymium, or terbium will be removed from theconversion coating solution when treating a smaller surface area ofmetal, so more work pieces can be coated from the same solution.

The corrosion-inhibiting cerium, praseodymium, or terbium compoundsformed on the surface of the metal exhibit solubilities ranging fromapproximately 5×10⁻² to 5×10⁻⁵ moles/liter of cerium, praseodymium, orterbium in water. Coating solutions with cerium, praseodymium, orterbium concentrations much less than these concentrations may: 1)withdraw cerium, praseodymium, or terbium from the formed coating inorder to attempt to reach an equilibrium, or 2) may produce anincomplete, poorly formed oxide film. Intentionally exhausted (depleted)conversion coating solutions have been observed to degrade a coatedsurface and return cerium, praseodymium, or terbium to the coatingsolution. The lowest concentration of cerium, praseodymium, or terbiumin the precursor conversion coating bath from which some resultantcorrosion inhibition will be exhibited is probably in the range of1×10⁻³ to 1×10⁻⁴ moles/liter of cerium, praseodymium, or terbium. Weused cerium concentrations of approximately 1×10⁻¹ mole/liter of ceriumwith excellent results.

3) Oxidizer Concentration

The concentration of the oxidizer source can range up to the maximumsolubility of the specific oxidizer source used. Any concentrationexceeding this solubility will result in undissolved solid material thatwill not be available to raise the redox potential of the conversioncoating solution. This process is designed to operate at ambienttemperatures, so the maximum concentration of oxidizer source should berestricted to its maximum solubility in water at or near ambienttemperature (25° C.). As discussed above, more oxidizer can be added tothe conversion coating solution if the temperature of the bath isincreased from ambient. Higher temperatures may lead to higher allowableconcentrations of oxidizer precursors, but this is unnecessary andundesirable in light of process economics. Table 4 shows thesolubilities in water of some of the more desirable oxidizer sources.

TABLE 4 Solubilities of Some Oxidizer Sources under Ambient Conditions(At or near 25° C. and at or near pH 7) Oxidizer Source ExamplePrecursor Solubility in Water (mole/L) A) Peroxides and SuperoxidesHydrogen peroxide 60 wt. % Lithium peroxide     1 × 10⁰ Sodium peroxide    1 × 10⁰ Potassium superoxide     1 × 10⁰ B) Persulfates Ammoniumpersulfate    2.6 × 10⁰ Lithium persulfate     3 × 10⁰ Sodium persulfate   3.1 × 10⁰ Potassium persulfate    2.0 × 10⁻¹ Magnesium persulfate    1 × 10¹ Calcium persulfate     1 × 10¹ Strontium persulfate     5 ×10⁰ Barium persulfate    1.3 × 10⁰ C) Perborates Ammonium perborate   1.8 × 10⁻¹ Lithium perborate     1 × 10⁻¹ Sodium perborate    1.7 ×10⁻¹ Potassium perborate    1.1 × 10⁻¹ D) PeroxybenzoatesMonoperoxyphthalic acid     1 × 10¹ Magnesium monoperoxyphthalate     1× 10¹ Chloroperoxybenzoic acid     1 × 10¹ E) Chlorites Lithium chlorite    5 × 10⁰ Sodium chlorite    4.3 × 10⁰ Calcium chlorite     1 × 10⁰Strontium chlorite     5 × 10⁻¹ Barium chlorite     1 × 10⁻¹ F) BromatesAmmonium bromate     1 × 10¹ Lithium bromate   4.85 × 10⁰ Sodium bromate  1.82 × 10⁰ Potassium bromate    8.0 × 10⁻¹ Rubidium bromate    1.4 ×10⁻¹ Cesium bromate    1.4 × 10⁻¹ Magnesium bromate    1.0 × 10⁰ Calciumbromate     1 × 10⁰ Strontium bromate    9.1 × 10⁻¹ Zinc bromate     1 ×10⁰ Ferric bromate   ~1 × 10⁰ G) Hypochlorites Lithium hypochlorite    1 × 10¹ Sodium hypochlorite     1 × 10¹ Magnesium hypochlorite     1× 10¹ Calcium hypochlorite     1 × 10¹ Strontium hypochlorite     5 ×10⁰ Barium hypochlorite     5 × 10⁰ H) Periodates Periodic acid   4.96 ×10¹ Ammonium periodate    1.3 × 10⁻¹ Lithium periodate     1 × 10⁰Sodium periodate    6.7 × 10⁻¹ Potassium periodate    2.9 × 10⁻²Rubidium periodate    2.4 × 10⁻² Cesium periodate    6.6 × 10⁻²Magnesium periodate     1 × 10⁻² I) Permanganates Ammonium permanganate  5.77 × 10⁻¹ Lithium permanganate   3.97 × 10⁰ Sodium permanganate    1 × 10⁰ Potassium permanganate   4.04 × 10⁻¹ Magnesium permanganate    1 × 10¹ Calcium permanganate   9.18 × 10⁰ Strontium permanganate  7.67 × 10⁰ Barium permanganate   2.01 × 10⁰ Zinc permanganate   8.10 ×10⁻¹ Ferric permanganate   ~1 × 10⁰ J) Chlorates Lithium chlorate    5.5× 10¹ Sodium chlorate    7.5 × 10⁰ Potassium chlorate    5.8 × 10⁻¹Rubidium chlorate    3.0 × 10⁻¹ Cesium chlorate    2.9 × 10⁻¹ Magnesiumchlorate    4.3 × 10⁰ Calcium chlorate    7.4 × 10⁰ Strontium chlorate   6.9 × 10⁰ Zinc chlorate    8.6 × 10⁰ Barium chlorate    8.5 × 10⁻¹ K)Perchlorates Perchloric acid 75 wt. % Ammonium perchlorate    1.3 × 10⁰Lithium perchlorate    5.6 × 10⁰ Sodium perchlorate    1.5 × 10¹Potassium perchlorate    3.6 × 10⁻¹ Rubidium perchlorate    2.2 × 10⁻¹Cesium perchlorate    8.6 × 10⁻² Magnesium perchlorate    4.4 × 10⁰Calcium perchlorate    7.9 × 10⁰ Strontium perchlorate    1.1 × 10¹ Zincperchlorate   ~1 × 10⁰ Barium perchlorate    5.1 × 10⁰ Aluminumperchlorate   ~1 × 10⁰ Ferric perchlorate   ~1 × 10⁰ Tetramethylammoniumperchlorate   ~1 × 10⁰ Tetraethylammonium perchlorate   ~5 × 10⁻¹Tetrapropylammonium perchlorate   ~1 × 10⁻¹ L) Nitrates Nitric acid 75wt. % Ammonium nitrate    2.5 × 10¹ Lithium nitrate    1.3 × 10¹ Sodiumnitrate    1.1 × 10¹ Potassium nitrate    7.4 × 10⁰ Rubidium nitrate   3.0 × 10⁰ Cesium nitrate    2.1 × 10⁰ Magnesium nitrate    4.9 × 10⁰Calcium nitrate    2.1 × 10¹ Strontium nitrate    3.4 × 10⁰ Zinc nitrate   6.2 × 10⁰ Barium nitrate    3.3 × 10⁻¹ Aluminum nitrate    1.7 × 10⁰Ferric nitrate    5.7 × 10⁰ Tetramethylammonium nitrate   ~1 × 10¹Tetraethylammonium nitrate   ~5 × 10⁰ Tetrapropylammonium nitrate   ~1 ×10⁰ Tetrabutylammonium nitrate   ~5 × 10⁻¹ M) Nitrites Lithium nitrite   2.8 × 10¹ Sodium nitrite    1.3 × 10¹ Potassium nitrite    3.5 × 10¹Magnesium nitrite   ~1 × 10⁰ Calcium nitrite    3.9 × 10⁰ Strontiumnitrite    3.8 × 10⁰ Zinc nitrite   ~1 × 10⁰ Barium nitrite    2.9 × 10⁰N) Vanadates Vanadium pentoxide    4.4 × 10⁻² Ammonium vanadate    4.4 ×10⁻² Lithium vanadate   ~1 × 10⁰ Sodium vanadate    1.7 × 10⁰ Potassiumvanadate   ~1 × 10⁰ Magnesium vanadate   ~1 × 10⁰ Calcium vanadate   ~5× 10⁻¹ O) Iodates Iodic acid   1.76 × 10¹ Iodine pentoxide    5.6 × 10⁰Ammonium iodate     1 × 10⁻¹ Lithium iodate    4.4 × 10⁰ Sodium iodate   4.5 × 10⁻¹ Potassium iodate    2.2 × 10⁻¹ Magnesium iodate    2.3 ×10⁻¹

Low oxidizer concentrations may not oxidize a sufficient quantity ofcerium, praseodymium, or terbium from the trivalent state to thetetravalent state. This would result in reduced corrosion-inhibitingperformance. The net redox potential of the coating solution is also afunction of the surface area of the metal that has been coated. Theredox potential decreases over time (e.g., several days), so thesesolutions typically need additions of oxidizer to maintain the redoxpotential.

4) Preparative Agent Concentration

The concentration of the preparative agent is desirable for theconversion coating process. Cratering of the coated metal surface hasbeen found when the solution concentration of the preparative agentexceeds (or even approaches) the solubility of the precursor material.This cratering results in coatings with reduced corrosion resistance.Solubility values for many fluorides (a typical preparative agent) aregiven in Table 5. The added concentrations should not exceed (or comeclose to) these values. Of course, variations in the solutiontemperature and pH will change the solubilities of each of thesepreparative agents, but the values given below can be used as generalapproximations.

TABLE 5 Solubilities of Fluoride Preparative Agents under AmbientConditions [Maximum Allowable Concentrations in Solution] (At or near25° C. and at near pH 7) Solubility in Water Fluoride Source ExamplePrecursor (mole/L) A) Simple Fluorides Hydrofluoric acid 75 wt. %Ammonium fluoride    2.7 × 10¹ Lithium fluoride   1.04 × 10⁻¹ Sodiumfluoride   1.01 × 10⁰ Potassium fluoride   1.59 × 10¹ Potassiumbifluoride   5.25 × 10⁰ Rubidium fluoride   1.25 × 10¹ Cesium fluoride  2.42 × 10¹ Copper (II) fluoride   4.62 × 10⁻¹ Silver (I) fluoride  1.43 × 10¹ Zinc fluoride   1.57 × 10⁻¹ Aluminum fluoride    6.6 × 10⁻²Titanium fluoride     1 × 10⁰ Zirconium fluoride    8.3 × 10⁻² Germaniumfluoride hydrate     1 × 10⁻¹ Tin (II) fluoride     1 × 10⁻¹ Tin (IV)fluoride     1 × 10⁰ Vandium fluoride     1 × 10⁻¹ Niobium fluoride    1 × 10⁰ Tantalum fluoride     1 × 10⁻¹ Antimony (III) fluoride  3.15 × 10⁻¹ Antimony (V) fluoride     1 × 10⁻¹ Manganese (II) fluoride   7.1 × 10⁻² Cobalt (II) fluoride   1.55 × 10⁻¹ B) HexafluorozirconatesAmmonium hexafluorozirconate     1 × 10⁻¹ Lithium hexafluorozirconate    8 × 10⁻² Sodium hexafluorozirconate     6 × 10⁻² Potassiumhexafluorozirconate   8.12 × 10⁻² Rubidium hexafluorozirconate   8.48 ×10⁻² Cesium hexafluorozirconate   1.12 × 10⁻¹ C) HexafluorotitanatesAmmonium hexafluorotitanate   ~1 × 10⁻¹ Lithium hexafluorotitanate   ~5× 10⁻² Sodium hexafluorotitanate   ~1 × 10⁻² Potassiumhexafluorotitanate    6.0 × 10⁻² Rubidium hexafluorotitanate    2.5 ×10⁻² Cesium hexafluorotitanate    5.5 × 10⁻² D) HexafluorosilicatesAmmonium hexafluorosilicate   1.04 × 10⁰ Lithium hexafluorosilicate   3.8 × 10⁰ Sodium hexafluorosilicate    3.5 × 10⁻² Potassiumhexafluorosilicate    5.5 × 10⁻³ Rubidium hexafluorosilicate    6.9 ×10⁻³ Cesium hexafluorosilicate    2.3 × 10⁻² Silver (I)hexafluorosilicate     1 × 10⁻⁰ Magnesium hexafluorosilicate    3.9 ×10⁰ Calcium hexafluorosilicate     1 × 10⁻¹ Strontium hexafluorosilicate   1.2 × 10⁻¹ Zinc hexafluorosilicate     1 × 10⁰ Copper (II)hexafluorosilicate    7.4 × 10⁰ Cobalt (II) hexafluorosilicate   3.82 ×10⁰ Manganese (II) hexafluorosilicate   4.59 × 10⁰ Iron (II)hexafluorosilicate   4.19 × 10⁰ Iron (III) hexafluorosilicate   4.19 ×10⁰ E) Hexafluoroaluminates Ammonium hexafluoroaluminate    5.3 × 10⁻²Lithium hexafluoroaluminate    6.6 × 10⁻³ Sodium hexafluoroaluminate   2.9 × 10⁻³ Potassium hexafluoroaluminate    6.1 × 10⁻³ F)Tetrafluoroborates Ammonium tetrafluoroborate    2.4 × 10⁰ Lithiumtetrafluoroborate     1 × 10⁰ Sodium tetrafluoroborate    9.8 × 10⁰Potassium tetrafluoroborate    3.5 × 10⁻² G) HexafluorogermanatesAmmonium hexafluorogermanates     1 × 10⁻¹ Potassiumhexafluorogermanates    2.0 × 10⁻² Rubidium hexafluorogermanates     1 ×10⁻² Cesium hexafluorogermanates     1 × 10⁻² H) HexafluorostannatesAmmonium hexafluorostannate     1 × 10⁻¹ Lithium hexafluorostannate    1 × 10⁻² Sodium hexafluorostannate     1 × 10⁻² Potassiumhexafluorostannate   1.28 × 10⁻¹ Rubidium hexafluorostannate    6.2 ×10⁻² Cesium hexafluorostannate    7.9 × 10⁻² I) HexafluorohafnatesAmmonium hexafluorohafnate     1 × 10⁰ Lithium hexafluorohafnate     1 ×10⁻¹ Sodium hexafluorohafnate     7 × 10⁻² Potassium hexafluorohafnate   1.3 × 10⁻¹ Rubidium hexafluorohafnate    1.9 × 10⁻¹ Cesiumhexafluorohafnate    1.7 × 10⁻¹ J) Hexafluorogallates Ammoniumfluorogallate     1 × 10⁻² Alkali/Alkaline fluorogallates     1 × 10⁻²Silver (I) fluorogallate     1 × 10⁰ Copper (II) fluorogallate     1 ×10⁻² Zinc fluorogallate     1 × 10⁻¹ Manganese (II), iron (II), andcobalt     1 × 10⁻² (II) fluorogallates K) Hexafluorophosphates Ammoniumhexafluorophosphate     1 × 10⁰ Lithium hexafluorophosphate     2 × 10⁰Sodium hexafluorophosphate    5.6 × 10⁰ Potassium hexafluorophosphate   5.1 × 10⁻¹ Rubidium hexafluorophosphate     1 × 10⁻¹ Cesiumhexafluorophosphate     1 × 10⁻¹ L) Hexafluoroantimonates Ammoniumhexafluoroantimonate    4.7 × 10⁰ Lithium hexafluoroantimonate     1 ×10⁰ Sodium hexafluoroantimonate   4.97 × 10⁰ Potassiumhexafluoroantimonate    3.7 × 10⁰ Rubidium hexafluoroantimonate    1.6 ×10⁰ Cesium hexafluoroantimonate     5 × 10⁰ M) HeptafluoroniobatesLithium heptafluoroniobate     5 × 10⁻¹ Sodium heptafluoroniobate     5× 10⁻² Potassium heptafluoroniobate    2.6 × 10⁻¹ Rubidiumheptafluoroniobate     1 × 10⁻¹ Cesium heptafluoroniobate     3 × 10⁻¹N) Heptafluorotantalates Lithium heptafluorotantalate     5 × 10⁻¹Sodium heptafluorotantalate     5 × 10⁻² Potassium heptafluorotantalate    3 × 10⁻¹ Rubidium heptafluorotantalate     1 × 10⁻¹ Cesiumheptafluorotantalate     3 × 10⁻¹

The concentration of preparative agent must be sufficient to treat theselected surface because the preparative agent initiates the entirecoating process. Low fluoride ion concentrations result in thin coatingsthat do not exhibit an acceptable degree of corrosion inhibition. Thesubstrate metal remains smooth and bright, and no visible coating actiontakes place at very low fluoride ion concentrations. These effects werefound to begin when the ratio of fluoride ions to cerium ions in thecoating solution falls below a ratio of 0.05. Therefore, the minimumrecommended fluoride-to-cerium, fluoride-to-praseodymium, orfluoride-to-terbium ratio is 0.05.

5) Valence Stabilizer Concentration

The concentration of the valence stabilizer can be any concentration upto the maximum solubility of the specific valence stabilizer sourceused. Any concentration exceeding this solubility will result inundissolved solid material that will not be available for stabilizingthe desired tetravalent cerium, praseodymium, or terbium ions. Sincethis process was developed to operate at ambient temperature, theconcentration of valence stabilizer source should be restricted to itsmaximum solubility in water at or near ambient temperature (25° C.).Higher temperatures may allow more valence stabilizer to be added to theconversion coating solution, but this is unnecessary and adds additionalcost to the process. Table 6 shows the aqueous solubilities of some ofthe more desirable sources for wide band (typical) inorganic valencestabilizers, and Table 7 shows the aqueous solubilities of some sourcesfor narrow band (less typical) inorganic valence stabilizers.

TABLE 6 Solubilities of Wide Band Inorganic Valence StabilizerPrecursors under Ambient Conditions [Maximum Allowable Concentrations inSolution] (At or near 25° C. and at or near pH 7) Inorganic Solubilityin Water Valence Stabilizer Example Precursors (mole/L) MolybdatesMolybdenum trioxide    7.4 × 10⁻³ Molybdic acid    7.4 × 10⁻³ Ammoniummolybdate     5 × 10⁰ Lithium molybdate     1 × 10¹ Sodium molybdate  2.15 × 10² Potassium molybdate   7.75 × 10² Rubidium molybdate    6.4× 10⁰ Cesium molybdate    4.8 × 10⁰ Magnesium molybdate    7.4 × 10⁻¹Tungstates Tungstic acid    8.0 × 10⁻¹ Ammonium tungstate     1 × 10²Lithium tungstate    5.8 × 10¹ Sodium tungstate   2.49 × 10² Potassiumtungstate   1.42 × 10² Rubidium tungstate     5 × 10¹ Cesium tungstate    5 × 10⁰ Magnesium tungstate hydrate    7.2 × 10⁻¹ Vanadates Vanadiumpentoxide    4.4 × 10⁻² Ammonium vanadate    4.4 × 10⁻² Lithium vanadate    1 × 10⁰ Sodium vanadate    1.7 × 10⁰ Potassium vanadate     1 × 10⁰Rubidium vanadate     5 × 10⁻¹ Cesium vanadate     5 × 10⁻¹ Magnesiumvanadate     1 × 10⁰ Calcium vanadate     5 × 10⁻¹ Niobates Ammoniumniobate     1 × 10⁻¹ Lithium niobate     1 × 10⁻¹ Sodium niobate    5.9× 10⁻² Potassium niobate     5 × 10⁻² Magnesium hexaniobate    8.8 ×10⁻² Calcium hexaniobate    4.7 × 10⁻² Tantalates Ammonium tantalate    1 × 10⁻² Lithium tantalate     1 × 10⁻² Sodium tantalate    5.5 ×10⁻³ Potassium tantalate     5 × 10⁻³ Tellurates Telluric acid     5 ×10⁻¹ Ammonium tellurate     5 × 10⁻¹ Lithium tellurate     1 × 10⁰Sodium tellurate    2.8 × 10⁻² Potassium tellurate     1 × 10⁻² Rubidiumtellurate     1 × 10⁻² Cesium tellurate     1 × 10⁻² Periodates Periodicacid   4.96 × 10¹ Ammonium periodate    1.3 × 10⁻¹ Lithium periodate    5 × 10¹ Sodium periodate    6.7 × 10⁻¹ Potassium periodate    2.9 ×10⁻² Rubidium periodate    2.4 × 10⁻² Cesium periodate    6.6 × 10⁻²Magnesium periodate     5 × 10⁰ Antimonates Ammonium antimonate     1 ×10⁰ Lithium antimonate     1 × 10⁰ Sodium antimonate    1.2 × 10⁻³Potassium antimonate   1.04 × 10⁻¹ Rubidium antimonate     1 × 10⁻¹Cesium antimonate     5 × 10⁻² Stannates Ammonium stannate     5 × 10⁰Lithium stannate     5 × 10⁰ Sodium stannate    2.3 × 10⁰ Potassiumstannate    3.7 × 10⁰ Rubidium stannate     5 × 10⁰ Cesium stannate    1 × 10⁰ Iodates Iodic acid   1.76 × 10¹ Iodine pentoxide    5.6 ×10⁰ Ammonium iodate     1 × 10⁻¹ Lithium iodate    4.4 × 10⁰ Sodiumiodate    4.5 × 10⁻¹ Potassium iodate    2.2 × 10⁻¹ Rubidium iodate   8.1 × 10⁻² Cesium iodate    8.4 × 10⁻² Magnesium iodate   2.29 × 10⁻¹Phosphates Phosphoric acid    5.6 × 10¹ Ammonium phosphate    1.3 × 10⁰Lithium phosphate    3.4 × 10⁻³ Sodium phosphate    2.6 × 10⁻¹ Potassiumphosphate    4.2 × 10⁰ Pyrophosphoric acid    4.0 × 10¹ Sodiumpyrophosphate    1.2 × 10⁻¹ Bromates Ammonium bromate     1 × 10¹Lithium bromate   4.85 × 10⁰ Sodium bromate   1.82 × 10⁰ Potassiumbromate    8.0 × 10⁻¹ Rubidium bromate    1.4 × 10⁻¹ Cesium bromate   1.4 × 10⁻¹ Magnesium bromate    1.0 × 10⁰ Calcium bromate     1 × 10⁰Strontium bromate    9.1 × 10⁻¹ Zinc bromate     1 × 10⁰ Ferric bromate  ~1 × 10⁰ Nitrates Nitric acid 75 wt. % Ammonium nitrate    2.5 × 10¹Lithium nitrate    1.3 × 10¹ Sodium nitrate    1.1 × 10¹ Potassiumnitrate    7.4 × 10⁰ Rubidium nitrate    3.0 × 10⁰ Cesium nitrate    2.1× 10⁰ Magnesium nitrate    4.9 × 10⁰ Calcium nitrate    2.1 × 10¹Strontium nitrate    3.4 × 10⁰ Zinc nitrate    6.2 × 10⁰ Barium nitrate   3.3 × 10⁻¹ Aluminum nitrate    1.7 × 10⁰ Ferric nitrate    5.7 × 10⁰Tetramethylammonium nitrate   ~1 × 10¹ Tetraethylammonium nitrate   ~5 ×10⁰ Tetrapropylammonium nitrate   ~1 × 10⁰ Tetrabutylammonium nitrate  ~5 × 10⁻¹ Sulfates Sulfuric acid 75 wt. % Ammonium sulfate    6.1 ×10⁰ Lithium sulfate    2.7 × 10⁰ Sodium sulfate    2.2 × 10⁰ Potassiumsulfate    1.0 × 10⁰ Rubidium sulfate    1.7 × 10⁰ Cesium sulfate    5.0× 10⁰ Magnesium sulfate    3.0 × 10⁰ Zinc sulfate    3.4 × 10⁰ Aluminumsulfate    3.0 × 10⁰ Ferric sulfate    7.9 × 10⁰ Carbonates Ammoniumcarbonate    8.8 × 10⁰ Ammonium bicarbonate    1.5 × 10⁰ Lithiumcarbonate    2.1 × 10⁻¹ Lithium bicarbonate    8.1 × 10⁻¹ Sodiumcarbonate    7.5 × 10⁻¹ Sodium bicarbonate    8.2 × 10⁻¹ Potassiumcarbonate    8.1 × 10⁰ Potassium bicarbonate    3.9 × 10⁰ Rubidiumcarbonate   1.95 × 10¹ Rubidium bicarbonate    3.7 × 10⁰ Cesiumcarbonate    8.0 × 10⁰ Cesium bicarbonate   1.08 × 10¹

TABLE 7 Solubilities of Narrow Band Inorganic Valence StabilizerPrecursors under Ambient Conditions (Maximum concentration in solutionat or near 25° C. and pH 7) Narrow Band Inorganic Valence Solubility inWater Stabilizer Example Precursors (mole/L) A) Germanates Germaniumdioxide hydrate    4.3 × 10⁻² Ammonium germanate   ~1 × 10⁰ Lithiumgermanate    6.3 × 10⁻² Sodium germanate   1.55 × 10⁰ Potassiumgermanate   ~1 × 10⁰ Rubidium germanate   ~5 × 10⁻¹ Cesium germanate  ~5 × 10⁻² B) Titanates Titanium hydroxide   1.36 × 10⁻⁴ C) ZirconatesZirconium hydroxide   1.26 × 10⁻³ D) Selenates Selenic acid 60 wt. %Ammonium selenate    6.0 × 10⁰ Sodium selenate    1.2 × 10⁰ Potassiumselenate    5.0 × 10⁰ E) Bismuthates Bismuth nitrate    2.7 × 10⁻²Bismuthyl perchlorate   ~1 × 10⁻¹ F) Arsenates Arsenic pentoxide    6.5× 10⁰ Ammonium arsenate    2.1 × 10⁰ Sodium arsenate    9.2 × 10⁻¹Potassium arsenate    7.4 × 10⁻¹ G) Silicates Sodium silicate   ~1 × 10⁰Potassium silicate   ~1 × 10⁰ H) Borates Boric acid     1 × 10⁰ Ammoniumborate    2.8 × 10⁻¹ Lithium borate    5.2 × 10⁻¹ Sodium borate    3.9 ×10⁰ Potassium borate    8.7 × 10⁰ I) Aluminates Sodium aluminate   ~1 ×10⁰ Potassium aluminate   ~1 × 10⁰

The number of complexing octahedra or icosahedra around the centralCe⁺⁴, Pr⁺⁴, or Tb⁺⁴ ion varies from species to species (e.g., molybdatesvs. tungstates). Varying the concentration of the complexing agent whilekeeping the Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴ concentration constant resulted in cleardifferences in corrosion protection. The degree of corrosion protectionwas found to fall off dramatically below a valence stabilizer-to-ceriumratio of about 0.01. Therefore, the minimum recommended valencestabilizer-to-cerium, valence stabilizer-to-praseodymium, or valencestabilizer-to-terbium ratio is 0.010, with ratios higher than 0.015being typical.

The maximum concentration of organic valence stabilizers is dependentupon the precursor solubility. Because of the very large number ofpotential organic valence stabilizers, precursor solubilities are notshown. The minimum concentration of valence stabilizer is dependent uponthe specific Ce⁺⁴—, Pr⁺⁴—, or Tb⁺⁴-valence stabilizer complex beingformed within the conversion coating. The solubility and maximumsolution concentration of these materials also increases withtemperature, but this increased temperature is unnecessary to produce aneffective coating.

6) Solubility Control Agent Concentration

The concentration of the optional solubility control agent can be anyconcentration up to its maximum solubility under ambient conditions.Exceeding the solubility will result in undissolved solid material thatwill not be available for adjusting the solubility of the cerium-,praseodymium-, or terbium-stabilizer complex. The solubilities ofpotential solubility control agents are not shown because of the largenumber of cationic or anionic species which can be used. Standard valuesfor the solubilities of these materials in water can be used as themaximum allowable concentrations in the prepared solutions.

7) Coating Solution pH

The conversion coating solution should have an acidic or neutral pH sothat a rise in pH caused by oxide and metal dissolution from the worksurface will result in a rise in local pH and the precipitation of thedesired conversion coating materials. Solution pH must not be so lowthat the pH rise during the conversion coating process is insufficientto result in coating precipitation. Very low pH values in the conversioncoating solutions may also lead to excessive substrate metal loss andpossible hydrogen embrittlement of the work piece.

The maximum practical pH of the conversion coating solution is about 7and the lowest practical pH is −1.5 for tetravalent cerium,praseodymium, or terbium coating application. Optimally, however, the pHshould not be higher than 6 or less than 1 or 2. The pH of thetetravalent cerium, praseodymium, or terbium conversion coatingsolutions should be checked periodically to confirm that it falls withinoperational parameters. Separate solutions that contain either valencestabilizers or optional solubility control agents generally do notrequire careful pH control.

8) Redox Potential of the Coating Solution

The necessary redox potential of the conversion coating solution is afunction of both the solution pH and the cerium, praseodymium, orterbium concentration. Approximate values for the necessary redoxpotential of the solution for cerium can be derived from the Pourbaixstability diagram for cerium. These values are shown in Table 8.Tetravalent cerium may be produced in solution at slightly lower redoxvalues than those in Table 8 if the cerium is already complexed withsuitable valence stabilizers. Tetravalent praseodymium or terbium mayalso be formed in a coating, provided that the redox potential issufficiently high, and that the optimum valence stabilizer for Pr⁺⁴ orTb⁺⁴ is used. An approximate value of the necessary redox potential forPr⁺⁴ or Tb⁺⁴ can be derived by adding 0.3 to 0.4 V to those shown inTable 8.

TABLE 8 Approximate Redox Potential as a Function of Conversion CoatingSolution pH Minimum pH Redox Potential (V) 0 1.7 1 1.6 2 1.5 3 1.3 4 1.15 1.0 6 0.8 7 0.7

These redox potentials can be achieved through chemical (orelectrochemical) means. The redox potential of the conversion coatingsolution will slowly drop over a period of several days. It should bebrought back up to those values shown in Table 8 when this happens.Periodic evaluation of the redox potential of these solutions can beperformed using ASTM D-1498 (Oxidation-Reduction Potential of Water) orcomparable test procedures. Post-treatment solutions that containvalence stabilizers or optional additional solubility control agentsgenerally do not require control of the redox potential.

9) Application Temperature

The recommended application temperature range of the conversion coatingsolution is between 5 to 40° C., with temperatures at or near ambient(20 to 25° C.) being typical. Application temperatures that are coolerthan the typical range will result in a much slower coating depositionrate and may result in incomplete film formation. Temperatures higherthan ambient can be used, but this is unnecessary and can increase thecost and application difficulty associated with the process. Atemperature range of between about 5 and about 100° C. thereforeconstitutes the maximum allowable range for the application of theseprocesses.

10) Contact Time, Coating Thickness

The contact time for the solutions should be sufficient to allow theformation of a uniform conversion coating of sufficient thickness to beeffective as both a barrier film and a reservoir of Ce⁺⁴, Pr⁺⁴, or Tb⁺⁴corrosion inhibitor. An average time of about 5 minutes has been foundeffective. A minimum solution contact time has been found to be about 1minute under ambient conditions. Contact times will vary with parametersincluding solution concentrations, temperature, pH, and alloycomposition. The barrier oxide film needs to develop long enough toprovide a suitable base for mechanical adhesion of a later paint layer.Incomplete coating deposition will result in coatings with reducedmechanical adhesion. A satisfactory conversion coating has a combinationof coating thickness and coating morphology that provides for goodadherence of the conversion coating as well as to subsequently appliedpaints and coatings. The state-of-the-art chromium conversion coatingsexhibit a coating thickness of approximately 200 nanometers, as well asa “mud-crack” or “honeycomb” morphology. Thinner coatings may beacceptable, but their morphology must be enhanced to achieve comparablepaint adhesion. The minimum thickness of a tetravalent cerium,praseodymium, or terbium coating will vary with substrate composition. Alower limit will be approximately 25 nanometers to form a pin-hole freeuniform coating that will promote paint adhesion. Conversely, very thickconversion coatings can result in low mechanical adhesion due tofracture through the grown films. The maximum thickness for asatisfactory tetravalent cerium, praseodymium, or terbium conversioncoating is approximately 10,000 nanometers.

C) General Application Process

The general process flow diagram for the application of the optimizedtetravalent cerium, praseodymium, or terbium conversion coatings is asfollows:

1) Precleaning (if required)

2) Masking (if required)

3) Alkaline cleaning/rinsing (if required)

4) Deoxidizing/rinsing (if required)

5) Formation of optimized tetravalent cerium, praseodymium, or terbiumconversion coating

6) Rinsing

7) Post-coating treatment

8) Rinsing

9) Drying (if required).

Each of these processing steps are discussed briefly as follows:

1) Precleaning (If Required)

Oils or greases on the part to be coated are removed using anappropriate technique, such as vapor degreasing.

2) Masking (If Required)

Any areas that are not to be conversion coated with the cerium,praseodymium, or terbium conversion coatings are masked off usingappropriate maskants. Any system component which may be adverselyaffected by the cerium, praseodymium, or terbium conversion coatingprocess should also be masked off.

3) Alkaline Cleaning/Rinsing or Other Cleaning Process (If Required)

Alkaline cleaning is suggested to remove traces of oils or hydrocarboncontaminants on the metal surface. These alkaline cleaning solutionsfrequently need elevated temperatures for application. The metal pieceshould be rinsed thoroughly following alkaline cleaning.

4) Deoxidizing/Rinsing (If Required)

Deoxidizing should be performed using appropriate deoxidizing solutionsin accordance with performance specifications in order to remove thenatural oxide film on the surface of the metal piece. Followingdeoxidizing, the metal piece is thoroughly rinsed while reducing as muchdrag-out as possible from the deoxidizing bath.

5) Formation of Cerium, Praseodymium, or Terbium Conversion Coating

The conversion coating solution (as described above) is applied throughimmersion, spray application, fogging, or manual application.

6) Rinsing

Standard rinse procedures are used.

7) Post-Coating Treatment

Solution formulations can be developed where a valence stabilizer is notincluded in the initial conversion coating solution or additionalsolubility control agents are needed to modify compounds formed duringcoating deposition. A second solution application (either by immersion,spray application, fogging, or manual application) may be necessary.This second solution would contain the cerium, praseodymium, or terbiumvalence stabilizer or solubility control agent.

Post coating treatments to the formed conversion coating can alsoinclude treatments to change the color of the formed coating through theaction of dyes or bleaching agents. For example, thick hexavalentchromium conversion coatings on zinc are often dyed black from theoriginal olive-drab color as-formed on the galvanized work piece.Likewise, bleaching agents are applied to hexavalent chromium conversioncoatings on zinc to obtain a clear or iridescent effect. The applicationof dyes or bleaching agents to conversion coatings based on tetravalentcerium, praseodymium, or terbium will change the color of these coatingsalso. Brighteners include such materials as sulfonic acids, sulfonates,sulfonamides, sulfinic acids, sulfinates, sulfones, cyanides, andnonionic surfactants.

8) Rinsing

Standard rinse procedures are used.

9) Drying (If Required)

Standard drying methods may be used. The state-of-the-art hexavalentchromium coatings require a 24-hour “aging” period prior to paintapplication. Comparable “aging” is optional but typical for cerium,praseodymium, or terbium conversion coatings.

EXAMPLES

In order that the invention may be more readily understood, reference ismade to the following examples, which are intended to illustrate theinvention, but not limit the scope thereof. Moreover, these examples arenot intended to represent refined final commercial compositions. Theyare intended to demonstrate the range and robustness of the Ce⁺⁴, Pr⁺⁴,and Tb⁺⁴ valence stabilization for conversion coatings of the presentinvention.

We present first the conditions by which many of our examples wereformed, the conditions under which their corrosion resistance wastested, and the color exhibited by many of the example tetravalentcerium conversion coatings. We then present some comparative examples ofprior art references that were examined during the development programassociated with the present application. Finally, some examples usingeither inorganic or organic valence stabilizers with Ce⁺⁴ are discussed.

1. Stock Solution and Sample Preparation

The test examples explored here (with the exception of the comparativeexamples) were all prepared in the same manner to avoid preparation andcompositional complications during analysis of stabilizer or preparationagent performance. Ammonium cerium nitrate [(NH₄)₂Ce(NO₃)₆] was thecompound used for the water-soluble cerium source (although many otherscould be used). The same quantity of potassium hexafluorozirconatepreparative agent was used as is in the CrVI baseline solution.

The following were held constant for all of the conversion coatingsolution formulations:

Ammonium cerium nitrate 78.9 grams - yielding 0.1440 M CeIV Potassiumhexafluorozirconate 1.70 grams

The reagents were added to one liter of deionized water at roomtemperature and allowed to dissolve while monitoring solutiontemperature and pH. Degreased and deoxidized plates of bare 2024-T3 and7075-T6 aluminum alloys were conversion coated with a specifictreatment. Multiple samples of specific compositions were prepared andtested. Exposure results reflect the average combined performance of thespecimens rather than a best performance. Ease of use, uniformapplication methodology, and predictable corrosion-inhibitingperformance are emphasized by using multiple samples. The usefulness ofthese conversion-coating methods depends on the ability to obtain aconstant level of corrosion inhibition. Samples treated with Alodine®1200 were prepared identically to those used to test CeIV compositionvariations for purposes of comparison.

Conversion coating performance would be, ideally, independent of thesubstrate composition. This is not necessarily seen when bare 2024T3 and7075-T6 aluminum alloys are tested side-by-side, with either CrVI orCeIV conversion coatings. Substrate composition can influence theeffectiveness of a particular conversion coat, but the limited selectionof chromate compound solubilities has restricted the general developmentof application-specific CrVI conversion coatings. The technologypresented here will allow the development of both effectivewide-spectrum coating systems for general application and tailoredcoating system solutions for specific needs, all based on tetravalentcerium (praseodymium or terbium).

2. Corrosion Testing

Conversion coat formulations were evaluated by static salt fog (ASTMB-117) and cyclic Prohesion™ (ASTM G-85.5) accelerated corrosion tests.ASTM B-117 is a traditional corrosion proof test, but it has littlerelation to a real working environment. This accelerated corrosion testexposes samples to a constant salt-water fog and is a defacto test ofsolubility for corrosion inhibitors. B-117 does not necessarily test theability of a corrosion inhibitor to actually inhibit corrosion. This isparticularly true of inhibitors and complexes that have not been fullyoptimized with respect to solubility. ASTM G-85.5 (Prohesion™) is acyclic corrosion test that more closely resembles real workingenvironments. This accelerated corrosion test exposes samples to a cycleof fog of dilute salt and ammonium sulfate at room temperature followedby forced-air drying at an elevated temperature. This is a true test ofthe ability of a compound to inhibit corrosion. Results of these testsmay be combined to gain insight into how a particular coating orcompound will perform relative to a standard, as well as helping toidentify strengths and weaknesses in the performance of a particularmaterial.

3. Color

Coating deposition may be identified by a change in surface texture orcolor. Commercial CrVI conversion coating systems are known to provide agolden, yellowish (for current systems), or greenish (for older systems)tint to the metal surface after treatment. The usefulness of color inthese coatings is as a visual aid during application and as a placemarker after application. The methods of forming conversion coatingsdescribed here are capable of producing colored or uncoloredcorrosion-inhibiting coatings.

4. Comparative Example 1

Alodine® 1200 is a commercial CrV1-ferricyanide based conversion coatingused extensively to provide corrosion protection to metal surfaces. Thismaterial was used as a performance baseline for the effectiveness ofCeIV compositions developed using the methodology described herein.Table 9 presents the accelerated corrosion testing results for bare2024-T3 and 7075-T6 aluminum alloy test panels treated with Alodine®1200 to form corrosion-inhibiting conversion coatings.

TABLE 9 Alodine ® 1200 Test Results for Accelerated Corrosion B-117B-117 G-85.5 G-85.5 Alloy Hours Rating Hours Rating 2024-T3 98  98% 16885% 7075-T6 98 100% 168 90%

The Alodine 1200 treated samples performed well during their period ofexposure as is expected from the current state-of-the-art. The influenceof alloy composition on the performance of the conversion coating becameclear over the period of exposure testing.

5. Comparative Example 2

Conversion coating processes based on cerium have been reported in theprior art that make use of oxidation or anodization of cerium-containingsolutions. Oxidation of these solutions without the presence of avalence stabilizer will result in the formation of tetravalent ceriumoxide, hydrated tetravalent cerium oxide, or tetravalent ceriumhydroxide within the formed coating. However, due to their extremely lowsolubilities, these species provide an insufficient quantity oftetravalent cerium to achieve coating repair. Tetravalent cerium oxide,hydrated tetravalent cerium oxide, or tetravalent cerium hydroxide serveas effective barrier layers until they are breached.

Coating solutions were prepared following the procedure described inU.S. Pat. No. 5,192,374; U.S. Pat. No. 5,932,083; and PCT InternationalPublication No. WO 88/06639. For the comparative sample 2-1(U.S. Pat.No. 5,192,374), a one weight percent solution of lithium nitrate, oneweight percent solution of aluminum nitrate, and 0.1 weight percentsolution of cerium(III) nitrate were placed into deionized water, thesolution was brought to boiling, and cleaned samples of bare 2024-T3 aswell as 7075-T6 aluminum alloys were immersed for 5 minutes. Forcomparative example 2-2 (U.S. Pat. No. 5,932,083), 25.6 grams ofcerium(III) nitrate was dissolved in a solution comprised of 960 mldeionized water, 960 ml propylene glycol, and 80 ml of 35 wt. % hydrogenperoxide. This solution was also heated to boiling, and precleaned2024-T3 and 7075-T6 aluminum alloys were immersed for 15 minutes.Finally, a comparative sample 2-3 (WO 88/06639) was prepared by adding5.8 grams of cerium(III) nitrate to a solution composed of 417 mldeionized water and 83 ml of 35 wt. % hydrogen peroxide. This solutionwas also heated to near boiling, and the aluminum alloy samples wereimmersed for 15 minutes. The coated samples were then exposed to ASTMB-117 and G-85 accelerated corrosion test environments. The specimensfailed to inhibit corrosion during accelerated corrosion testing in ASTMG-85. Some minor corrosion inhibition was noted in ASTM B-117 due to thebarrier film formed by the coating processes. For example, the samplesprepared using the procedure described in WO 88/06639 were observed tobe slightly more effective on the 7075 aluminum alloy than on the 2024aluminum sample.

A variation of this process was also examined (i.e., PCT InternationalPublication No. WO 01/38225) wherein finely divided tetravalent ceriumoxide polishing powders were placed into deionized water to form acolloidal suspension. The aluminum species noted above were placed intothese solutions at both room and elevated temperatures. The coatedsamples were exposed to ASTM B-117 and G-85 accelerated corrosion testenvironments. The specimens failed to inhibit corrosion duringaccelerated corrosion testing in ASTM G-85. Some minor corrosioninhibition was noted in ASTM B-117 due to the barrier film formed by thecoating processes. Depending on the size of the added tetravalent ceriumoxide particles, minor deviations in performance could be observed inASTM B-117.

Detailed analysis of the prior art process (WO 01/38225) determined thatheating the coating solutions in the presence of oxidizer was a methodof producing a tetravalent cerium oxide barrier coating. However, theoxides that form from the high temperature solution described in thisprior art reference will be starved of available CeIV due to theextremely low solubilities of these species.

6. Comparative Example 3

Polymers or other film-formers (i.e., silicon-based materials) have beenused in prior art conversion coating solutions in association withcerium (i.e., European Application No. EP 0 792 922 A1). Film-formersmay enhance short-term corrosion resistance by functioning as a barrierlayer. CeIV-based conversion coating solutions of proven effectivenesswere prepared with film forming additives. A periodate 2× valencestabilized CeIV conversion coating solution was mixed with a polyvinylbutyral resin with an acid diluent and applied to test specimens. TheCeIV-periodate valence stabilizer system yields a good conversioncoating. Likewise, a molybdate-cerium conversion coating was mixed witha non-inhibitive film former (available from Zip Chem Products,Indianapolis, Ind.) and applied to test specimens. The depositedperiodate/polyvinyl butyral resin film had a low viscosity and did notset up as a film for two days after solution application. Table 10 showsthe results of accelerated corrosion testing on this barrier filmsystem.

TABLE 10 Exposure Results for Barrier Film CeIV Formulations 2024-T37075-76 2024-T3 7075-T6 B-117 B-117 G-85 G-85 Stabilizer 135 hrs. 135hrs. 135 hrs. 135 hrs. Periodate 2x in polyvinyl 12% 12% 55% 20% butyralresin Periodate 2x in polyvinyl 12% 12% 55% 20% butyral resin

The molybdate-cerium conversion coating that was mixed with anon-inhibitive film former never set and remained liquid 2 weeks afterapplication.

Detailed analysis of the prior art process determined that the filmformers interfere with substrate oxidation during the conversion coatingprocess. Thin, incompletely anodized surfaces are formed that restrictthe incorporation of a reservoir for active corrosion inhibitor. Acomparison of these results with periodate compositions with no polymerindicates that the compositions with no polymer exhibit much greatercorrosion resistance.

7. Comparative Example 4

Conversion coating processes based on cerium have been reported in theprior art that make use of electrolysis of cerium-containing solutions.Electrolysis of these solutions without the presence of a valencestabilizer will result in the formation of tetravalent cerium oxide,hydrated tetravalent cerium oxide, or tetravalent cerium hydroxidewithin the formed coating. Due to their extremely low solubilities,these species provide an insufficient quantity of tetravalent cerium toachieve coating repair. Tetravalent cerium oxide, hydrated tetravalentcerium oxide, or tetravalent cerium hydroxide serve as effective barrierlayers until they are breached.

Coating solutions were prepared following the procedure described inU.S. Pat. No. 5,194,138. For the comparative sample 4-1, two solutionscomprised of 2.18 grams of cerium(III) nitrate dissolved in 500 mldeionized water and 2.0 grams of cerium(III) chloride dissolved in 500ml deionized water were prepared. When in use, these solutions wereheated to 80° C. Precleaned 2024-T3 and 7075-T6 aluminum samples wereimmersed in the heated cerium nitrate solution for one hour followed byone hour in the heated cerium chloride solution. For comparative example4-2, a third solution composed of 10.3 grams sodium molybdate in 500 mldeionized water was also prepared and heated to 80° C. For comparativeexample 4-2, the precleaned aluminum pieces were immersed in solutionsone and two for the allotted time at the required temperature, thentransferred to the third solution where a constant potential 500 mV morepositive than the aluminum samples was applied for one hour. A thirdcoating process (4-3), not specified in the prior art, was performed byelectrolyzing the aluminum samples in the prepared cerium(III) nitratesolutions for one hour at 80° C. The coated samples were exposed to ASTMB-117 and G-85 accelerated corrosion test environments. The specimensfailed to inhibit corrosion during accelerated corrosion testing in ASTMG-85. Some minor corrosion inhibition was noted in ASTM B-117 due to thebarrier film formed by the coating processes. Slightly higher corrosionresistance in ASTM G-85 was noted for the samples that had beenelectrolyzed in the molybdate solution.

Detailed analysis of the prior art process determined that electrolyzingthe coating solutions in the presence of oxidizer was a method ofproducing a tetravalent cerium oxide barrier coating. However, theoxides that form from high temperature solution in this prior artreference will be starved of available CeIV due to the extremely lowsolubilities of these species. Subsequent electrolysis in a molybdatesolution produced minor amounts of a cerium(IV) molybdate species on theexterior of the formed coating. Because the majority of the depositedcerium was deposited in the form of an insoluble cerium(IV) oxide, andbecause the quantity of cerium(IV) molybdate produced was relativelysmall (only on the exterior of the coating), only limited corrosionresistance was observed.

8. Example 1 CeIV Solubility Range

Three factors influence the effectiveness of CeIV complexes as activecorrosion inhibitors. These factors are the solubility, valencestabilization, and polar character of the formed complex. Valencestabilization is necessary for the formation of useful inhibitors. Thecomplex will simply not be able to oxidize surface flaws if the valenceis not stabilized. The polar character of the complex is an importantbut not an essential feature of a corrosion-inhibiting complex.

Complexes lacking significant electrostatic double layer formation arestill able to provide some amount of active inhibition. CeIV complexavailability is second only to valence stabilization in a conversioncoating's ability to provide effective inhibition. The solubility ofsolid CeIV complexes controls both how much and how fast corrosioninhibitor is supplied to a corroding surface. Solubility ranges forinhibitors have been referred to as insoluble, sparingly soluble, andvery soluble. Sparingly soluble compounds are known to offer the widestrange of useful oxidizer in solution.

A test to identify the range of CeIV availability in solution needed toinhibit corrosion was performed by preparing a series of simplecomplexes with valence stabilization and polar character held constant.Conversion coating solutions containing CeIV as the oxidizing componentwere prepared where the CeIV ion was valence stabilized in solution withnitrate alone. Six nitrate molecules are known to pack around solubleCeIV forming a hexanitrato-cerium (Ce(NO₃)₆ ⁻²) complex. The cationicspecies tetramethylammonium (4 total carbons), tetraethylammonium (8total carbons), tetrapropylammonium (12 total carbons),tetrabutylammonium (16 total carbons), tetrapentylammonium (20 totalcarbons), and Adogen 464 (25 total carbons) were used to precipitateCo(NO₃)₆ ⁻² complexes of varying solubility. Hydroxide was also used toprepare hydrated cerium(IV) oxide- and cerium(IV) hydroxide-containingcoatings. Coating solutions containing potassium hexafluorozirconate asa surface preparative agent were applied to cleaned 2024-T3 aluminumsamples. The coated samples were exposed to 135 hours of ASTM B-117 and135 hours of G-85 accelerated corrosion test environments.

A clear progression of corrosion resistance was observed.CeO₂.xH₂O/Ce(OH)₄ was precipitated when the hexanitratocerate complexwas reacted with hydroxide. The samples containing extremely insolubleCeO₂.xH₂O/Ce(OH)₄ exhibited little or no corrosion resistance. Samplesthat contained the more soluble hexanitratocerate species (i.e.,tetramethylammonium and tetraethylammonium) performed well in the earlystages of the test, but failed to inhibit corrosion part way into thecorrosion test. Solubilities as high as about 5×10⁻¹ moles/liter of CeIVexhibited corrosion resistance during the early portion of acceleratedcorrosion testing, but failed later in the test. The higher solubilitycomplexes would have promoted rapid CeIV depletion as the testprogressed.

Intermediate solubility complexes of tetrapropylammonium,tetrabutylammonium, and tetrapentylammonium hexanitratocerate speciesexhibited corrosion resistance greater than tetramethylammonium andtetraethylammonium stabilized complexes and performed the best of thisseries of stabilizer cations. These exhibited greater corrosionresistance than samples containing tetramethylammonium ortetraethylammonium. This data allowed an approximate range of 5×10⁻² to5×10⁻⁵ moles/liter of CeIV to be established as a typical solubilityrange for solid CeIV complexes in conversion coatings. Generally, CeIVcomplex solubility ranges as high as 5×10⁻¹to as low as 1×10⁻⁵ moles perliter of CeIV, at standard temperature and pressure, may offer somecorrosion protection under certain conditions. An approximate solubilityrange of 5×10⁻² to 5×10⁻⁵ moles/liter of CeIV in solution is a desirablesolubility range for CeIV in conversion coatings.

It should be noted that we also performed similar tests using depositedCrVI compounds of varying solubility. As with the CeIV coatings, a clearprogression of performance based on solubility was observed.

9. Example 2 Inorganic Stabilizers

Inorganic valence stabilizers were used to test and verify the method offorming effective CeIV-based conversion coatings. A series of simpleinorganic valence stabilized CeIV complexes were prepared and applied toprecleaned bare 2024-T3 and 7075-T6 aluminum alloy samples. Immersiontimes were 5 minutes for each piece in each formulation. The coatedsamples were exposed to ASTM B-117 and G-85 accelerated corrosion testenvironments. Table 11 shows the type and concentration of eachstabilizer that was used in combination with CeIV. The concentration ofeach stabilizer was either the same as that of ferricyanide in thehexavalent chromium formulations on a molar basis, or, in the case ofsome of the inorganics, twice that amount. This was done to ensuresufficient source material to form heteropolymetallates for CeIVstabilization within the coating.

TABLE 11 Formulations and Test Results for Initial CeIV Stabilizers2024-T3 7075-76 2024-T3 7075-T6 Stabilizer B-117 B-117 G-85 G-85Stabilizer Conc. 65 hrs. 65 hrs. 70 hrs. 70 hrs. Periodate 0.0050 M PassPass Pass Pass (Periodic acid) (1.16 g) Tellurate 0.0050 M Pass PassPass Pass (Telluric acid) (1.16 g) Molybdate 0.0100 M Pass Pass PassPass (Na molybdate) (2.32 g) Tungstate 0.0050 M Fail Fail Pass Pass (Natungstate) (0.40 g) Pass = 25% or more of all 3 panel surfacesuncorroded Fail = Less than 25% of all 3 panel surfaces uncorroded.

Three 2024-T3 and three 7075-T6 samples of each formulation were loadedfor ASTM B-117 salt fog exposure and ASTM G-85 Prohesion™ exposure. Thepanels were exposed for 65 hours in the ASTM B-117 Salt fog test and 70hours in the ASTM G-85 Prohesion™ test—a sufficient time period to beginto see the corrosion resistance of each coating for each alloy.

The periodate, molybdate, and tellurate-stabilized coatings performedwell. Some corrosion product formed on this series of samples but allsixteen sample coupons had large bare uncorroded areas. The periodateand molybdate samples exhibited corrosion protection comparable to theAlodine® 1200 treated specimens in both ASTM B-117 and ASTM G-85environments. The molybdate coatings also exhibited gold coloration,similar to those coatings derived from Alodine® 1200. Other inorganicstabilization agents also were effective to various degrees. Thetungstate-stabilized coatings demonstrated the influence of solubilityon the performance of the coating during salt fog exposure. Thisstabilizer is a candidate for further examination to tailor thesolubility of the complex with additional solubility control agents.

Solubility control agents were used to modify the solubility of formedcompounds. For example, a stock Ce⁺⁴/fluoride solution was preparedusing the proportions of ammonium cerium(IV) nitrate and potassiumhexafluorozirconate described at the beginning of this section. Secondsolutions containing both wide band (carbonate, phosphate, antimonite,stannate) and narrow band (silicate) valence stabilizers were prepared.These consisted of 10 grams of phosphoric acid, potassiumhexahydroxyantimonate, potassium hydrogen carbonate, or sodium silicatein 1 liter deionized water. A third solution consisting of either 10grams lithium nitrate or magnesium nitrate in 1 liter deionized waterwere prepared. The 2024-T3 or 7075-T6 aluminum samples were placed inthe first cerium/fluoride solution for 5 minutes at ambient temperature;rinsed; placed into the second solutions containing valence stabilizersfor 5 minutes at ambient temperature; rinsed; and then placed into thethird solutions containing solubility control agents for 5 minutes atambient temperatures. The panels were exposed for 100 hours in the ASTMB-117 Salt fog test and 100 hours in the ASTM G-85 Prohesion™ test—asufficient time period to begin to see the corrosion resistance of eachcoating for each alloy.

All samples prepared exhibited appreciable corrosion protection. Thecarbonate-stabilized samples exhibited corrosion protection approachingthat of hexavalent chromium. Even the narrow band valence stabilizer(silicate) samples exhibited corrosion protection approaching or equalto hexavalent chromium through the use of these two solubility controlagents (Li and Mg).

This set of samples demonstrates the robust character of the method ofpreparing CeIV-based conversion coatings described herein. Precursorconcentration does influence the corrosion resistance of coatings madewith these stabilizers. Several of these formulations are of commercialquality with no additional development or refinement necessary. Theworst of the chemical systems described work better than currentcommercial alternatives for CrV1-based conversion coatings. Thehexanitrato stabilized compositions could be used immediately as directequivalent replacements for Alodine 1200, as well as many of theformulations using lithium or magnesium as solubility control agents.The processes described do not invoke the use of extraneous processingconditions (boiling bath temperatures, applied electric currents) toachieve marginal performance results.

10. Example 3 Organic Valence Stabilizers

Organic valence stabilizers were used to verify the robustness of themethod of forming effective CeIV-based conversion coatings. Organiccompounds provide an almost unlimited number of possibilities forstabilizer compositions. The encouraging results with inorganicstabilizer compounds suggested the value of examining additional organicstabilizers. The concentration of the organic stabilizers were variedsimilar to inorganic valence stabilizers shown in the earlier example.Conversion coating solutions were prepared as described above. Thesesolutions were applied to precleaned bare 2024-T3 and 7075-T6 aluminumalloy samples. Immersion times were 5 minutes for each piece in eachformulation. The coated samples were exposed to ASTM G-85 acceleratedcorrosion test environments. Table 12 shows the type and concentrationof each organic stabilizer that was used for CeIV.

TABLE 12 Formulations and Test Results for Organic CeIV Stabilizers2024-T3 7075-T6 Stabilizer G-85 G-85 Stabilizer Conc. 121 hr min. 121 hrmin. Ferricyanide 1x (Potassium 0.0025 M 90% 85% ferricyanide) Flavazin2x (Flavazin dye) 0.0050 M 95% 80% Tartrazin 2x (Tartrazin dye) 0.0050 M95% 80% Metanil yellow 2x (Metanil dye) 0.0050 M 65% 85% Phthalocyanine1x 0.0025 M 65% 20% (Phthalocyanine dye) Diethyldithiocarbamate 1x0.0025 M 85% 75% Biuret 1x 0.0025 M 80% 60% Naphthol yellow 2x 0.0050 M90% 80%

The rating numbers correspond to chrome baselines exposed to the sameconditions (given a ranking of 100%).

Several of the large organic valence stabilizers approached and passedthe level of protection provided by Alodine® 1200 in ASTM G-85accelerated corrosion testing. Naphthol yellow-, tartrazin-, andflavazin-stabilized CeIV conversion coating performed better thanAlodine 1200 in ASTM G-85 for 2024-T3. The results for salt fog indicatethat solubility control is important in tailoring the long-termperformance of these compounds. Phthalocyanine, flavazin, and tartrazinewere very effective in ASTM G-85 and worked very well for a limited timein B-117. This result indicates that these materials are effective ininhibiting corrosion but may need additional solubility control to reachtheir full potential.

While the invention has been described by reference to certainembodiments, it should be understood that numerous changes could be madewithin the spirit and scope of the inventive concepts described.Accordingly, it is intended that the invention not be limited to thedisclosed embodiments, but that it have the full scope permitted by thelanguage of the following claims.

1. A solid corrosion-inhibiting conversion coating formed on a substratemetal, the conversion coating comprising a rare earth element and aninorganic valence stabilizer combined to form a rare earth/valencestabilizer complex within the solid corrosion-inhibiting conversioncoating, wherein the rare earth element is selected from cerium,praseodymium, terbium, or a combination thereof, and at least one rareearth element is in the tetravalent oxidation state in the rareearth/valence stabilizer complex in the solid corrosion-inhibitingconversion coating.
 2. The conversion coating of claim 1 wherein therare earth/valence stabilizer complex has a solubility in water ofbetween about 5×10⁻¹ and about 1×10⁻⁵ moles per liter of cerium,praseodymium, or terbium at about 25° C. and about 760 Torr.
 3. Theconversion coating of claim 2 wherein the solubility of the rareearth/valence stabilizer complex in water is between about 5×10⁻² andabout 5×10⁻⁵ moles per liter of cerium, praseodymium, or terbium atabout 25° C. and about 760 Torr.
 4. The conversion coating of claim 1wherein there is an electrostatic barrier layer around the rareearth/valence stabilizer complex in aqueous solution.
 5. The conversioncoating of claim 1 wherein the rare earth/valence stabilizer complexacts as an ion exchange agent towards corrosive ions.
 6. The conversioncoating of claim 1 wherein the conversion coating is between about 25and about 10,000 nanometers thick.
 7. The conversion coating of claim 6wherein the conversion coating is between about 100 and about 500nanometers thick.
 8. The conversion coating of claim 1 wherein theconversion coating has a morphology which enhances adhesion of a coatingapplied over the conversion coating.
 9. The conversion coating of claim1 wherein the rare earth/valence stabilizer complex has a central cavitycontaining a cerium, praseodymium, or terbium ion and an additional ion.10. The conversion coating of claim 9 wherein the additional ion is B⁺³,Al⁺³, Si⁺⁴, P⁺⁵, Ti⁺⁴, V⁺⁵, V⁺⁴, Cr⁺⁶, Cr⁺³, Mn⁺⁴, Mn⁺³, Mn⁺², Fe⁺³,Fe⁺², Co⁺², Co⁺³, Ni⁺² , Ni⁺³, Ni⁺⁴, Cu⁺², Cu⁺³, Zn⁺², Ga⁺³, Ge⁺⁴, As⁺⁵,As⁺³, or Zr⁺⁴.
 11. The conversion coating of claim 1 wherein theinorganic valence stabilizer is selected from molybdates, tungstates,vanadates, niobates, tantalates, tellurates, periodates, iodates,carbonates, antimonates, stannates, phosphates, nitrates, bromates,sulfates, titanates, zirconates, bismuthates, germanates, arsenates,selenates, borates, aluminates, silicates, or combinations thereof. 12.The conversion coating of claim 11 wherein the valence stabilizer is theinorganic valence stabilizer selected from molybdates, tungstates,vanadates, niobates, tantalates, tellurates, periodates, iodates,carbonates, antimonates, stannates, phosphates, nitrates, bromates,sulfates, or combinations thereof.
 13. The conversion coating of claim 1wherein the rare earth/valence stabilizer complex further comprises asolubility control agent.
 14. The conversion coating of claim 13 whereinthe solubility control agent is a cationic solubility control agent oran anionic solubility control agent.
 15. The conversion coating of claim14 wherein the solubility control agent is the cationic solubilitycontrol agent selected from H⁺; Li⁺; Na⁺; K⁺; Rb⁺; Cs⁺; NH₄ ⁺; Mg⁺²;Ca⁺²; Sr⁺²; Be⁺²; Ba⁺²; Y⁺³; La⁺³; Ce⁺³; Ce⁺⁴; Nd⁺³; Pr⁺³; Sc⁺³; Sm⁺³;Eu⁺³; Eu⁺²; Gd⁺³; Tb⁺³; Dy⁺³; Ho⁺³; Er⁺³; Tm⁺³; Yb⁺³; Lu⁺³; Ti⁺⁴; Zr⁺⁴;Ti⁺³; Hf⁺⁴; Nb⁺⁵; Ta⁺⁵; Nb⁺⁴; Ta⁺⁴; V⁺⁵; V⁺⁴; V⁺³; Mo⁺⁶; W⁺⁶; Mo⁺⁵; W⁺⁵;Mo⁺⁴; W⁺⁴; Cr⁺³; Mn⁺²; Mn⁺³; Mn⁺⁴; Fe⁺²; Fe⁺³; Co⁺²; Co⁺³; Ni⁺²; Ni⁺³;Ni⁺⁴; Ru⁺²; Ru⁺³; Ru⁺⁴; Rh⁺³; Ir⁺³; Rh⁺²; Ir⁺²; Pd⁺⁴; Pt⁺⁴; Pd⁺²; Pt⁺²;Os⁺⁴; Cu⁺; Cu⁺²; Cu⁺³; Ag⁺; Ag⁺²; Ag⁺³; Au⁺; Au⁺²; Au⁺³; Zn⁺²; Cd⁺²;Hg⁺; Hg⁺²; Al⁺³; Ga⁺³; Ga⁺; In⁺³; In⁺; Tl⁺³; Tl⁺; Ge⁺⁴; Ge⁺²; Sn⁺⁴;Sn⁺²; Pb⁺⁴; Pb⁺²; Sb⁺³; Sb⁺⁵; As⁺³; As⁺⁵; Bi⁺³; Bi⁺⁵; organic compoundscontaining at least one N⁺ site; organic compounds containing at leastone phosphonium site; organic compounds containing at least one arsoniumsite; organic compounds containing at least one stibonium site; organiccompounds containing at least one oxonium site; organic compoundscontaining at least one sulfonium site; organic compounds containing atleast one selenonium site; organic compounds containing at least oneiodonium site; quaternary ammonium compounds having a formula NR₄ ⁺,where R is an alkyl, aromatic, or acyclic organic constituent; orcombinations thereof.
 16. The conversion coating of claim 15 wherein thecationic solubility control agent is selected from H⁺; Li⁺; Na⁺; K⁺;Rb⁺; Cs⁺; NH₄ ⁺; Mg⁺²; Ca⁺²; Sr⁺²; Y⁺³; La⁺³; Ce⁺³; Nd⁺³; Pr⁺³; Sc⁺³;Sm⁺³; Eu⁺³; Eu⁺²; Gd⁺³; Tb⁺³; Dy⁺³; Ho⁺³; Er⁺³; Tm⁺³; Yb⁺³; Lu⁺³; Ti⁺⁴;Zr⁺⁴; Ti⁺³; Hf⁺⁴; Nb⁺⁵; Ta⁺⁵; Nb⁺⁴; Ta⁺⁴; Mo⁺⁶; W⁺⁶; Mo⁺⁵; W⁺⁵; Mo⁺⁴;W⁺⁴; Mn⁺²; Mn⁺³; Mn⁺⁴; Fe⁺²; Fe⁺³; Co⁺²; Co⁺³; Ru⁺²; Ru⁺³; R⁺⁴; Rh⁺³;Ir⁺³; Rh⁺²; Ir⁺²; Pd⁺⁴; Pt⁺⁴; Pd⁺²; Pt⁺²; Cu⁺; Cu⁺²; Cu⁺³; Ag⁺; Ag⁺²;Ag⁺³; Au⁺; Au⁺²; Au⁺³; Zn⁺²; Al⁺³; Ga⁺³; Ga⁺; In⁺³; In⁺; Ge⁺⁴; Ge⁺²;Sn⁺⁴; Sn⁺²; Sb⁺³; Sb⁺⁵; Bi⁺³; Bi⁺⁵; organic compounds containing atleast one N⁺ site; organic compounds containing at least one phosphoniumsite; organic compounds containing at least one stibonium site; organiccompounds containing at least one oxonium site; organic compoundscontaining at least one sulfonium site; organic compounds containing atleast one iodonium site; quaternary ammonium compounds having a formulaNR₄ ⁺, where R is an alkyl, aromatic, or acyclic organic constituent; orcombinations thereof.
 17. The conversion coating of claim 14 wherein thesolubility control agent is the anionic solubility control agentselected from fluorotitanates, chlorotitanates, fluorozirconates,chlorozirconates, fluoroniobates, chloroniobates, fluorotantalates,chiorotantalates, molybdates, tungstates, permanganates,fluoromanganates, chloromanganates, fluoroferrates, chloroferrates,fluorocobaltates, chlorocobaltates, fluorozincates, chlorozincates,borates, fluoroborates, fluoroaluminates, chioroaluminates, carbonates,silicates, fluorosilicates, fluorostannates, nitrates, nitrites, azides,cyanamides, phosphates, phosphites, phosphonates, phosphinites,thiophosphates, thiophosphites, thiophosphonates, thiophosphinites,fluorophosphates, fluoroantimonates, chloroantimonates, sulfates,sulfites, sulfonates, thiosulfates, dithionites, dithionates,fluorosulfates, tellurates, fluorides, chlorides, chiorates,perchlorates, bromides, bromates, iodides, iodates, periodates,heteropolyanions, ferricyanides, ferrocyanides, cyanocobaltates,cyanocuprates, cyanomanganates, cyanates, cyanatoferrates,cyanatocobaltates, cyanatocuprates, cyanatomanganates, thiocyanates,thiocyanatoferrates, thiocyanatocobaltates, thiocyanatocuprates,thiocyanatomanganates, cyanamides, cyanamidoferrates,cyanamidocobaltates, cyanamidocuprates, cyanamidomanganates,nitritoferrates, nitritocobaltates, azides, (thio)carboxylates,di(thio)carboxylates, tri(thio)carboxylates, tetra(thio)carboxylates,(thio)phenolates, di(thio)phenolates, tri(thio)phenolates,tetra(thio)phenolates, (thio)phosphonates, di(thio)phosphonates,tri(thio)phosphonates, (thio)phosphonamides, di(thio)phosphonamides,tri(thio)phosphonamides, amino(thio)phosphonates,diamino(thio)phosphonates, triamino(thio)phosphonates,imino(thio)phosphonates, diimino(thio)phosphonates, (thio)sulfonates,di(thio)sulfonates, tri(thio)sulfonates, (thio)sulfonamides,di(thio)sulfonamides, tri(thio)sulfonamides, amino(thio)sulfonates,diamino(thio)sulfonates, triamino(thio)sulfonates,imino(thio)sulfonates, diimino(thio)sulfonates, (thio)borates,di(thio)borates, (thio)boronates, organic silicates, stibonates,cyanides, cyanoebromates, cyanonickelates, cyanatochromates,cyanatonickelates, thiocyanatochromates, thiocyanatonickelates,cyanamidochromates, cyanamidonickelates, nitritonickelates, arsonates,diarsonates, triarsonates, organic selenates, diselenates, triselenates,arsenates, arsenites, fluoroarsenates, chioroarsenates, selenates,selenites, fluorothallates, chiorothallates, iodomercury anions,chioromercurates, bromomercurates, osmates, fluoronickelates, chromates,Reinecke's salt, vanadates, or combinations thereof.
 18. The conversioncoating of claim 17 wherein the anionic solubility control agent isselected from fluorotitanates, chiorotitanates, fluorozirconates,chiorozirconates, fluoroniobates, chloroniobates, fluorotantalates,chlorotantalates, molybdates, tungstates, permanganates,fluoromanganates, chioromanganates, fluoroferrates, chloroferrates,fluorocobaltates, chlorocobaltates, fluorozincates, chlorozincates,borates, fluoroborates, fluoroaluminates, chloroaluminates, carbonates,silicates, fluorosilicates, fluorostannates, nitrates, nitrites, azides,cyanamides, phosphates, phosphites, phosphonates, phosphinites,thiophosphates, thiophosphites, thiophosphonates, thiophosphinites,fluorophosphates, fluoroantimonates, chloroantimonates, sulfates,sulfites, sulfonates, thiosulfates, dithionites, dithionates,fluorosulfates, tellurates, fluorides, chlorides, chlorates,perchiorates, bromides, bromates, iodides, iodates, periodates,heteropolyanions, ferricyanides, ferrocyanides, cyanocobaltates,cyanocuprates, cyanomanganates, cyanates, cyanatoferrates,cyanatocobaltates, cyanatocuprates, cyanatomanganates, thiocyanates,thiocyanatoferrates, thiocyanatocobaltates, thiocyanatocuprates,thiocyanatomanganates, cyanamides, cyanamidoferrates,cyanamidocobaltates, cyanamidocuprates, cyanamidomanganates,nitritoferrates, nitritocobaltates, azides, (thio)carboxylates,di(thio)carboxylates, tri(thio)carboxylates, tetra(thio)carboxylates,(thio)phenolates, di(thio)phenolates, tri(thio)phenolates,tetra(thio)phenolates, (thio)phosphonates, di(thio)phosphonates,tri(thio)phosphonates, (thio)phosphonamides, di(thio)phosphonamides,tri(thio)phosphonamides, amino(thio)phosphonates,diamino(thio)phosphonates, triamino(thio)phosphonates,imino(thio)phosphonates, diimino(thio)phosphonates, (thio)sulfonates,di(thio)sulfonates, tri(thio)sulfonates, (thio)sulfonamides,di(thio)sulfonamides, tri(thio)sulfonamides, amino(thio)sulfonates,diamino(thio)sulfonates, triamino(thio)sulfonates,imino(thio)sulfonates, diimino(thio)sulfonates, (thio)borates,di(thio)borates, (thio)boronates, organic silicates, stibonates, orcombinations thereof.
 19. The conversion coating of claim 1 wherein theconversion coating is colored.
 20. The conversion coating of claim 19further comprising an agent which improves color-fastness of theconversion coating.
 21. The conversion coating of claim 20 wherein theagent which improves color-fastness is selected from an active UVblocker, a passive UV blocker, a brightener, or a combination thereof.22. The conversion coating of claim 21 wherein the agent which improvescolor-fastness is the active UV blocker selected from carbon black,graphite, phthalocyanines, or combinations thereof.
 23. The conversioncoating of claim 21 wherein the agent which improves color-fastness isthe passive UV blocker selected from titanium oxide, tin oxide, leadoxide, silicon oxide, silicates, aluminosilicates, or combinationsthereof.
 24. The conversion coating of claim 21 wherein the agent whichimproves color-fastness is the brightener selected from sulfonic acids,sulfonates, sulfonamides, sulfinic acids, sulfinates, sulfones,cyanides, nonionic surfactants, or combinations thereof.
 25. Theconversion coating of claim 19 wherein the color is formed by a dyeselected from vat dyes, mordant dyes, lake dyes, disperse dyes, azodyes, triazene dyes, triphenylmethane dyes, azine dyes, formazan dyes,phthalocyanine dyes, Schiff Base dyes, naturally-occurring dyes,inorganic pigments, or combinations thereof.
 26. A solidcorrosion-inhibiting conversion coating formed on a substrate metal, theconversion coating comprising a rare earth element and an inorganicvalence stabilizer combined to form a rare earth/valence stabilizercomplex within the solid corrosion-inhibiting conversion coating,wherein the rare earth element is selected from cerium, praseodymium,terbium, or a combination thereof, at least one rare earth element is inthe tetravalent oxidation state in the rare earth/valence stabilizercomplex in the solid corrosion-inhibiting conversion coating, and therare earth/valence stabilizer complex is sparingly soluble in water atabout 25° C. and about 760 Torr.
 27. A solid corrosion-inhibitingconversion coating formed on a substrate metal, the conversion coatingcomprising a rare earth element and a valence stabilizer combined toform a rare earth/valence stabilizer complex within the solidcorrosion-inhibiting conversion coating, wherein the rare earth elementis selected from cerium, praseodymium, terbium, or a combinationthereof, and at least one rare earth element is in the tetravalentoxidation state, wherein the rare earth/valence stabilizer complex has acentral cavity containing a cerium, praseodymium, or terbium ion and anadditional ion, wherein the additional ion is B⁺³, Al⁺³, Si⁺⁴, P⁺⁵,Ti⁺⁴, V⁺⁵, V⁺⁴, Cr⁺⁶, Cr⁺³, Mn⁺⁴, Mn⁺³, Mn⁺², Fe⁺³, Fe⁺², Co⁺², Co⁺³,Ni⁺² , Ni⁺³, Ni⁺⁴, Cu⁺², Cu⁺³, Zn⁺², Ga⁺³, Ge⁺⁴, As⁺⁵, As⁺³, or Zr⁺⁴.28. The conversion coating of claim 27 wherein the rare earth/valencestabilizer complex has a solubility in water of between about 5×10⁻¹ andabout 1×10⁻⁵ moles per liter of cerium, praseodymium, or terbium atabout 25° C. and about 760 Torr.
 29. The conversion coating of claim 28wherein the solubility of the rare earth/valence stabilizer complex inwater is between about 5×10⁻² and about 5×10⁻⁵ moles per liter ofcerium, praseodymium, or terbium at about 25° C. and about 760 Torr. 30.The conversion coating of claim 27 wherein there is an electrostaticbarrier layer around the rare earth/valence stabilizer complex inaqueous solution.
 31. The conversion coating of claim 27 wherein therare earth/valence stabilizer complex acts as an ion exchange agenttowards corrosive ions.
 32. The conversion coating of claim 27 whereinthe conversion coating is between about 25 and about 10,000 nanometersthick.
 33. The conversion coating of claim 32 wherein the conversioncoating is between about 100 and about 500 nanometers thick.
 34. Theconversion coating of claim 27 wherein the conversion coating has amorphology which enhances adhesion of a coating applied over theconversion coating.
 35. The conversion coating of claim 27 wherein thevalence stabilizer is an inorganic valence stabilizer selected frommolybdates, tungstates, vanadates, niobates, tantalates, tellurates,periodates, iodates, carbonates, antimonates, stannates, phosphates,nitrates, bromates, sulfates, titanates, zirconates, bismuthates,germanates, arsenates, selenates, borates, aluminates, silicates, orcombinations thereof.
 36. The conversion coating of claim 35 wherein thevalence stabilizer is the inorganic valence stabilizer selected frommolybdates, tungstates, vanadates, niobates, tantalates, tellurates,periodates, iodates, carbonates, antimonates, stannates, phosphates,nitrates, bromates, sulfates, or combinations thereof.
 37. Theconversion coating of claim 27 wherein the rare earth/valence stabilizercomplex further comprises a solubility control agent.
 38. The conversioncoating of claim 37 wherein the solubility control agent is a cationicsolubility control agent or an anionic solubility control agent.
 39. Theconversion coating of claim 38 wherein the solubility control agent isthe cationic solubility control agent selected from H⁺; Li⁺; Na⁺; K⁺;Rb⁺; Cs⁺; NH₄ ⁺; Mg⁺²; Ca⁺²; Sr⁺²; Be⁺²; Ba⁺²; Y⁺³; La⁺³; Ce⁺³; Ce⁺⁴;Nd⁺³; Pr⁺³; Sc⁺³; Sm⁺³; Eu⁺³; Eu⁺²; Gd⁺³; Tb⁺³; Dy⁺³; Ho⁺³; Er⁺³; Tm⁺³;Yb⁺³; Lu⁺³; Ti⁺⁴; Zr⁺⁴; Ti⁺³; Hf⁺⁴; Nb⁺⁵; Ta⁺⁵; Nb⁺⁴; Ta⁺⁴; V⁺⁵; V⁺⁴;V⁺³; Mo⁺⁶; W⁺⁶; Mo⁺⁵; W⁺⁵; Mo⁺⁴; W⁺⁴; Cr⁺³; Mn⁺²; Mn⁺³; Mn⁺⁴; Fe⁺²;Fe⁺³; Co⁺²; Co⁺³; Ni⁺²; Ni⁺³; Ni⁺⁴; Ru⁺²; Ru⁺³; Ru⁺⁴; Rh⁺³; Ir⁺³; Rh⁺²;Ir⁺²; Pd⁺⁴; Pt⁺⁴; Pd⁺²; Pt⁺²; Os⁺⁴; Cu⁺; Cu⁺²; Cu⁺³; Ag⁺; Ag⁺²; Ag⁺³;Au⁺; Au⁺²; Au⁺³; Zn⁺²; Cd⁺²; Hg⁺; Hg⁺²; Al⁺³; Ga⁺³; Ga⁺; In⁺³; In⁺;Tl⁺³; Tl⁺; Ge⁺⁴; Ge⁺²; Sn⁺⁴; Sn⁺²; Pb⁺⁴; Pb⁺²; Sb⁺³; Sb⁺⁵; As⁺³; As⁺⁵;Bi⁺³; Bi⁺⁵; organic compounds containing at least one N⁺ site; organiccompounds containing at least one phosphonium site; organic compoundscontaining at least one arsonium site; organic compounds containing atleast one stibonium site; organic compounds containing at least oneoxonium site; organic compounds containing at least one sulfonium site;organic compounds containing at least one selenonium site; organiccompounds containing at least one iodonium site; quaternary ammoniumcompounds having a formula NR₄ ⁺, where R is an alkyl, aromatic, oracyclic organic constituent; or combinations thereof.
 40. The conversioncoating of claim 39 wherein the cationic solubility control agent isselected from H⁺; Li⁺; Na⁺; K⁺; Rb⁺; Cs⁺; NH₄ ⁺; Mg⁺²; Ca⁺²; Sr⁺²; Y⁺³;La⁺³; Ce⁺³; Nd⁺³; Pr⁺³; Sc⁺³; Sm⁺³; Eu⁺³; Eu⁺²; Gd⁺³; Tb⁺³; Dy⁺³; Ho⁺³;Er⁺³; Tm⁺³; Yb⁺³; Lu⁺³; Ti⁺⁴; Zr⁺⁴; Ti⁺³; Hf⁺⁴; Nb⁺⁵; Ta⁺⁵; Nb⁺⁴; Ta⁺⁴;Mo⁺⁶; W⁺⁶; Mo⁺⁵; W⁺⁵; Mo⁺⁴; W⁺⁴; Mn⁺²; Mn⁺³; Mn⁺⁴; Fe⁺²; Fe⁺³; Co⁺²;Co⁺³; Ru⁺²; Ru⁺³; R⁺⁴; Rh⁺³; Ir⁺³; Rh⁺²; Ir⁺²; Pd⁺⁴; Pt⁺⁴; Pd⁺²; Pt⁺²;Cu⁺; Cu⁺²; Cu⁺³; Ag⁺; Ag⁺²; Ag⁺³; Au⁺; Au⁺²; Au⁺³; Zn⁺²; Al⁺³; Ga⁺³;Ga⁺; In⁺³; In⁺; Ge⁺⁴; Ge⁺²; Sn⁺⁴; Sn⁺²; Sb⁺³; Sb⁺⁵; Bi⁺³; Bi⁺⁵; organiccompounds containing at least one N⁺ site; organic compounds containingat least one phosphonium site; organic compounds containing at least onestibonium site; organic compounds containing at least one oxonium site;organic compounds containing at least one sulfonium site; organiccompounds containing at least one iodonium site; quaternary ammoniumcompounds having a formula NR₄ ⁺, where R is an alkyl, aromatic, oracyclic organic constituent; or combinations thereof.
 41. The conversioncoating of claim 27 wherein the conversion coating is colored.
 42. Theconversion coating of claim 41 further comprising an agent whichimproves color-fastness of the conversion coating.
 43. The conversioncoating of claim 42 wherein the agent which improves color-fastness isselected from an active UV blocker, a passive UV blocker, a brightener,or a combination thereof.
 44. The conversion coating of claim 43 whereinthe agent which improves color-fastness is the active UV blockerselected from carbon black, graphite, phthalocyanines, or combinationsthereof.